From 7666dbb1bacc4ba522b96740cba7283d243d16e1 Mon Sep 17 00:00:00 2001 From: John Walker Date: Thu, 7 May 2026 17:07:20 -0600 Subject: wifi: cfg80211: advance loop vars in cfg80211_merge_profile() cfg80211_merge_profile() reassembles a Multi-BSSID non-transmitted BSS profile that has been split across multiple consecutive MBSSID elements. Its while-loop calls cfg80211_get_profile_continuation(ie, ielen, mbssid_elem, sub_elem) but never advances mbssid_elem or sub_elem inside the body. Each iteration therefore searches for a continuation that follows the same fixed pair; the helper returns the same next_mbssid; and the same next_sub bytes are memcpy()'d into merged_ie at a growing offset until the buffer fills. Advance both mbssid_elem and sub_elem to the just-consumed continuation so the next call to cfg80211_get_profile_continuation() searches for a further continuation beyond it (or returns NULL when none exists). A specially-crafted malicious beacon can take advantage of this bug to cause the kernel to spend an excessive amount of time in cfg80211_merge_profile (up to as much as 2ms per beacon received), which could theoretically be abused in some way. Cc: stable@vger.kernel.org Fixes: fe806e4992c9 ("cfg80211: support profile split between elements") Signed-off-by: John Walker Link: https://patch.msgid.link/20260507230720.64783-1-johnwalker0@gmail.com Signed-off-by: Johannes Berg --- net/wireless/scan.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 328af43ef832..358cbc9e43d8 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -2462,6 +2462,9 @@ size_t cfg80211_merge_profile(const u8 *ie, size_t ielen, memcpy(merged_ie + copied_len, next_sub->data, next_sub->datalen); copied_len += next_sub->datalen; + + mbssid_elem = next_mbssid; + sub_elem = next_sub; } return copied_len; -- cgit v1.2.3 From 94f3b133168d1c49895e7cc6afbcf1cc0b354602 Mon Sep 17 00:00:00 2001 From: Luxiao Xu Date: Mon, 11 May 2026 18:52:09 +0200 Subject: batman-adv: fix tp_meter counter underflow during shutdown batadv_tp_sender_shutdown() unconditionally decrements the "sending" atomic counter. If multiple paths (e.g. timeout, user cancel, and normal finish) call this function, the counter can underflow to -1. Since the sender logic treats any non-zero value as "still sending", a negative value causes the sender kthread to loop indefinitely. This leads to a use-after-free when the interface is removed while the zombie thread is still active. Fix this by using atomic_xchg() to ensure the counter only transitions from 1 to 0 once. Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Luxiao Xu Signed-off-by: Ren Wei [sven: added missing change in batadv_tp_send] Signed-off-by: Sven Eckelmann --- net/batman-adv/tp_meter.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index 066c76113fc4..a4397aa881dd 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -451,7 +451,7 @@ static void batadv_tp_sender_end(struct batadv_priv *bat_priv, static void batadv_tp_sender_shutdown(struct batadv_tp_vars *tp_vars, enum batadv_tp_meter_reason reason) { - if (!atomic_dec_and_test(&tp_vars->sending)) + if (atomic_xchg(&tp_vars->sending, 0) != 1) return; tp_vars->reason = reason; @@ -885,7 +885,7 @@ static int batadv_tp_send(void *arg) "Meter: %s() cannot send packets (%d)\n", __func__, err); /* ensure nobody else tries to stop the thread now */ - if (atomic_dec_and_test(&tp_vars->sending)) + if (atomic_xchg(&tp_vars->sending, 0) == 1) tp_vars->reason = err; break; } -- cgit v1.2.3 From 77098e4bea37af51d3962efa88a5af2ea5e1ac57 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sun, 10 May 2026 11:31:03 +0200 Subject: batman-adv: tp_meter: fix tp_vars reference leak in receiver shutdown The receiver shutdown timer handler, batadv_tp_receiver_shutdown(), is responsible for releasing the tp_vars reference it holds. However, the existing logic for coordinating this release with batadv_tp_stop_all() was flawed. timer_shutdown_sync() guarantees the timer will not fire again after it returns, but it returns non-zero only when the timer was pending at the time of the call. If the timer had already expired (and batadv_tp_stop_all() would unsucessfully try to rearm itself), batadv_tp_stop_all() skips its batadv_tp_vars_put(), and batadv_tp_receiver_shutdown() fails to put its own reference as well. Fix this by introducing a new atomic variable receiving that is set to 1 when the receiver is initialized and cleared atomically with atomic_xchg() by whichever side claims it first. Only the side that observes the transition from 1 to 0 is responsible for releasing the tp_vars timer reference, eliminating the uncertainty. Cc: stable@kernel.org Fixes: 3d3cf6a7314a ("batman-adv: stop tp_meter sessions during mesh teardown") Signed-off-by: Sven Eckelmann --- net/batman-adv/tp_meter.c | 13 +++++++++++-- net/batman-adv/types.h | 3 +++ 2 files changed, 14 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index a4397aa881dd..ca6c3f6374bc 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -8,6 +8,7 @@ #include "main.h" #include +#include #include #include #include @@ -1156,6 +1157,9 @@ static void batadv_tp_receiver_shutdown(struct timer_list *t) spin_unlock_bh(&tp_vars->unacked_lock); /* drop reference of timer */ + if (WARN_ON(atomic_xchg(&tp_vars->receiving, 0) != 1)) + return; + batadv_tp_vars_put(tp_vars); } @@ -1374,6 +1378,7 @@ batadv_tp_init_recv(struct batadv_priv *bat_priv, ether_addr_copy(tp_vars->other_end, icmp->orig); tp_vars->role = BATADV_TP_RECEIVER; + atomic_set(&tp_vars->receiving, 1); memcpy(tp_vars->session, icmp->session, sizeof(tp_vars->session)); tp_vars->last_recv = BATADV_TP_FIRST_SEQ; tp_vars->bat_priv = bat_priv; @@ -1546,8 +1551,12 @@ void batadv_tp_stop_all(struct batadv_priv *bat_priv) break; case BATADV_TP_RECEIVER: batadv_tp_list_detach(tp_var); - if (timer_shutdown_sync(&tp_var->timer)) - batadv_tp_vars_put(tp_var); + timer_shutdown_sync(&tp_var->timer); + + if (atomic_xchg(&tp_var->receiving, 0) != 1) + break; + + batadv_tp_vars_put(tp_var); break; } diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index daa06f421154..b9c0b7779122 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1323,6 +1323,9 @@ struct batadv_tp_vars { /** @sending: sending binary semaphore: 1 if sending, 0 is not */ atomic_t sending; + /** @receiving: receiving binary semaphore: 1 if receiving, 0 is not */ + atomic_t receiving; + /** @reason: reason for a stopped session */ enum batadv_tp_meter_reason reason; -- cgit v1.2.3 From 1e9fab756f8395096d5bba7be0c373c4c8f5d165 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 2 May 2026 19:08:37 +0200 Subject: batman-adv: tt: reject oversized local TVLV buffers The commit 3a359bf5c61d ("batman-adv: reject oversized global TT response buffers") added a check to ensure that a global return buffer size can be stored in an u16. The same buffer handling also exists for the local data buffer but was not touched. A similar check should be also be in place for the local TVLV buffer. It doesn't have the similar attack surface because it is only generated from locally discovered MAC addresses but the dynamic nature could still cause temporarily to large buffers. Cc: stable@kernel.org Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific") Signed-off-by: Sven Eckelmann --- net/batman-adv/translation-table.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 05cddcf994f6..06548dae1039 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -877,12 +877,12 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, { struct batadv_tvlv_tt_vlan_data *tt_vlan; struct batadv_meshif_vlan *vlan; + size_t change_offset; u16 num_vlan = 0; u16 vlan_entries = 0; u16 total_entries = 0; u16 tvlv_len; u8 *tt_change_ptr; - int change_offset; spin_lock_bh(&bat_priv->meshif_vlan_list_lock); hlist_for_each_entry(vlan, &bat_priv->meshif_vlan_list, list) { @@ -900,8 +900,10 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, if (*tt_len < 0) *tt_len = batadv_tt_len(total_entries); - tvlv_len = *tt_len; - tvlv_len += change_offset; + if (check_add_overflow(*tt_len, change_offset, &tvlv_len)) { + tvlv_len = 0; + goto out; + } *tt_data = kmalloc(tvlv_len, GFP_ATOMIC); if (!*tt_data) { -- cgit v1.2.3 From b64963a2ceeb7529310b6cf253a1e540784422f4 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 2 May 2026 19:53:21 +0200 Subject: batman-adv: tt: fix negative tt_buff_len batadv_orig_node::tt_buff_len was declared as s16, but the field is never intended to hold a negative value. When a value greater than 32767 is assigned, it wraps to a negative signed integer. In batadv_send_other_tt_response(), tt_buff_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_global_data() to allocate a full sized buffer but populates only a small portion of it with the collected changeset. All remaining bits are kept uninitialized. Using an u16 avoids this type confusion and ensures that no (negative) sign extension is performed in batadv_send_other_tt_response(). Cc: stable@kernel.org Fixes: a73105b8d4c7 ("batman-adv: improved client announcement mechanism") Signed-off-by: Sven Eckelmann --- net/batman-adv/types.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index b9c0b7779122..888f337a194b 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -452,7 +452,7 @@ struct batadv_orig_node { * @tt_buff_len: length of the last tt changeset this node received * from the orig node */ - s16 tt_buff_len; + u16 tt_buff_len; /** @tt_buff_lock: lock that protects tt_buff and tt_buff_len */ spinlock_t tt_buff_lock; -- cgit v1.2.3 From fc92cdfcb295cefa4344d71a527d61b638b7bfc4 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 2 May 2026 19:53:21 +0200 Subject: batman-adv: tt: fix negative last_changeset_len batadv_piv_tt::last_changeset_len len was declared as s16, but the field is never intended to hold a negative value. When a value greater than 32767 is assigned, it wraps to a negative signed integer. In batadv_send_my_tt_response(), last_changeset_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_local_data() to allocate a full sized buffer but populates only a small portion of it with the collected changeset. All remaining bits are kept uninitialized. Using an u16 avoids this type confusion and ensures that no (negative) sign extension is performed in batadv_send_my_tt_response(). Cc: stable@kernel.org Fixes: a73105b8d4c7 ("batman-adv: improved client announcement mechanism") Signed-off-by: Sven Eckelmann --- net/batman-adv/types.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 888f337a194b..739439e2b235 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -993,7 +993,7 @@ struct batadv_priv_tt { * @last_changeset_len: length of last tt changeset this host has * generated */ - s16 last_changeset_len; + u16 last_changeset_len; /** * @last_changeset_lock: lock protecting last_changeset & -- cgit v1.2.3 From 94d27005016be15ffc638b2ecbc4d58805ad7b48 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 2 May 2026 19:47:11 +0200 Subject: batman-adv: tt: fix TOCTOU race for reported vlans The local TT based TVLV is generated by first checking the number of VLANs which have at least one TT entry. A new buffer with the correct size for the VLANs is then allocated. Only then, the list of VLANs s used to fill the VLAN entries in the buffer. During this time, the meshif_vlan_list_lock is held. But the actual number of TT entries of each VLAN can still increase during this time - just not the number of VLANs in the list. But the prefilter used in the buffer size calculation might still cause an increase of the number of VLANs which need to be stored. Simply because a VLAN might now suddenly have at least one entry when it had none in the pre-alloc check - and then needs to occupy space which was not allocated. It is better to overestimate the buffer size at the beginning and then fill the buffer only with the VLANs which are not empty. Cc: stable@kernel.org Fixes: 16116dac2339 ("batman-adv: prevent TT request storms by not sending inconsistent TT TLVLs") Signed-off-by: Sven Eckelmann --- net/batman-adv/translation-table.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 06548dae1039..f009cbf8a276 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -887,11 +887,8 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, spin_lock_bh(&bat_priv->meshif_vlan_list_lock); hlist_for_each_entry(vlan, &bat_priv->meshif_vlan_list, list) { vlan_entries = atomic_read(&vlan->tt.num_entries); - if (vlan_entries < 1) - continue; - - num_vlan++; total_entries += vlan_entries; + num_vlan++; } change_offset = struct_size(*tt_data, vlan_data, num_vlan); @@ -916,6 +913,7 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, (*tt_data)->num_vlan = htons(num_vlan); tt_vlan = (*tt_data)->vlan_data; + num_vlan = 0; hlist_for_each_entry(vlan, &bat_priv->meshif_vlan_list, list) { vlan_entries = atomic_read(&vlan->tt.num_entries); if (vlan_entries < 1) @@ -926,8 +924,15 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, tt_vlan->reserved = 0; tt_vlan++; + num_vlan++; } + /* recalculate in case number of VLANs reduced */ + change_offset = struct_size(*tt_data, vlan_data, num_vlan); + tvlv_len = *tt_len + change_offset; + + (*tt_data)->num_vlan = htons(num_vlan); + tt_change_ptr = (u8 *)*tt_data + change_offset; *tt_change = (struct batadv_tvlv_tt_change *)tt_change_ptr; -- cgit v1.2.3 From fa1bd704940b5bcbc32c0b28db9167405c8ee5e0 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 2 May 2026 20:47:34 +0200 Subject: batman-adv: tt: avoid empty VLAN responses The commit 16116dac2339 ("batman-adv: prevent TT request storms by not sending inconsistent TT TLVLs") added checks to the local (direct) TT response code. But the response can also be done indirectly by another node using the global TT state. To avoid such inconsistency states reported in the original fix, also avoid sending empty VLANs for replies from the global TT state. Cc: stable@kernel.org Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific") Signed-off-by: Sven Eckelmann --- net/batman-adv/translation-table.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index f009cbf8a276..2259b241e0b5 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -797,24 +797,26 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, s32 *tt_len) { u16 num_vlan = 0; - u16 num_entries = 0; u16 tvlv_len = 0; unsigned int change_offset; struct batadv_tvlv_tt_vlan_data *tt_vlan; struct batadv_orig_node_vlan *vlan; + u16 total_entries = 0; u8 *tt_change_ptr; + int vlan_entries; spin_lock_bh(&orig_node->vlan_list_lock); hlist_for_each_entry(vlan, &orig_node->vlan_list, list) { + vlan_entries = atomic_read(&vlan->tt.num_entries); + total_entries += vlan_entries; num_vlan++; - num_entries += atomic_read(&vlan->tt.num_entries); } change_offset = struct_size(*tt_data, vlan_data, num_vlan); /* if tt_len is negative, allocate the space needed by the full table */ if (*tt_len < 0) - *tt_len = batadv_tt_len(num_entries); + *tt_len = batadv_tt_len(total_entries); if (change_offset > U16_MAX || *tt_len > U16_MAX - change_offset) { *tt_len = 0; @@ -835,14 +837,26 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, (*tt_data)->num_vlan = htons(num_vlan); tt_vlan = (*tt_data)->vlan_data; + num_vlan = 0; hlist_for_each_entry(vlan, &orig_node->vlan_list, list) { + vlan_entries = atomic_read(&vlan->tt.num_entries); + if (vlan_entries < 1) + continue; + tt_vlan->vid = htons(vlan->vid); tt_vlan->crc = htonl(vlan->tt.crc); tt_vlan->reserved = 0; tt_vlan++; + num_vlan++; } + /* recalculate in case number of VLANs reduced */ + change_offset = struct_size(*tt_data, vlan_data, num_vlan); + tvlv_len = *tt_len + change_offset; + + (*tt_data)->num_vlan = htons(num_vlan); + tt_change_ptr = (u8 *)*tt_data + change_offset; *tt_change = (struct batadv_tvlv_tt_change *)tt_change_ptr; -- cgit v1.2.3 From 99d9958fa10fb684b2a8e2c48a8d704122721420 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 2 May 2026 21:25:19 +0200 Subject: batman-adv: tt: prevent TVLV entry number overflow The helpers to prepare the buffers for the local and global TT based replies are trying to sum up all TT entries which can be found for each VLAN. In theory, this sum can be too big for an u16 and therefore overflow. A too small buffer would then be allocated for the TVLV. The too small buffer will be handled gracefully by batadv_tt_tvlv_generate() and is not causing a buffer overflow - just a truncated reply. But this overflow shouldn't have happened in the first and the too small buffer should never have been allocated when an overflow was detected. Cc: stable@kernel.org Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific") Signed-off-by: Sven Eckelmann --- net/batman-adv/translation-table.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 2259b241e0b5..9f6e67771ffa 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -804,11 +804,18 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, u16 total_entries = 0; u8 *tt_change_ptr; int vlan_entries; + u16 sum_entries; spin_lock_bh(&orig_node->vlan_list_lock); hlist_for_each_entry(vlan, &orig_node->vlan_list, list) { vlan_entries = atomic_read(&vlan->tt.num_entries); - total_entries += vlan_entries; + + if (check_add_overflow(vlan_entries, total_entries, &sum_entries)) { + *tt_len = 0; + goto out; + } + + total_entries = sum_entries; num_vlan++; } @@ -893,15 +900,22 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, struct batadv_meshif_vlan *vlan; size_t change_offset; u16 num_vlan = 0; - u16 vlan_entries = 0; u16 total_entries = 0; u16 tvlv_len; u8 *tt_change_ptr; + int vlan_entries; + u16 sum_entries; spin_lock_bh(&bat_priv->meshif_vlan_list_lock); hlist_for_each_entry(vlan, &bat_priv->meshif_vlan_list, list) { vlan_entries = atomic_read(&vlan->tt.num_entries); - total_entries += vlan_entries; + + if (check_add_overflow(vlan_entries, total_entries, &sum_entries)) { + tvlv_len = 0; + goto out; + } + + total_entries = sum_entries; num_vlan++; } -- cgit v1.2.3 From e83f5e24da741fa9405aeeff00b08c5ee7c37b88 Mon Sep 17 00:00:00 2001 From: Jiexun Wang Date: Wed, 6 May 2026 19:43:30 +0800 Subject: Bluetooth: serialize accept_q access bt_sock_poll() walks the accept queue without synchronization, while child teardown can unlink the same socket and drop its last reference. The unsynchronized accept queue walk has existed since the initial Bluetooth import. Protect accept_q with a dedicated lock for queue updates and polling. Also rework bt_accept_dequeue() to take temporary child references under the queue lock before dropping it and locking the child socket. Fixes: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: Jann Horn Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Jiexun Wang Signed-off-by: Ren Wei Signed-off-by: Jiexun Wang Reviewed-by: Jann Horn Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/af_bluetooth.c | 87 +++++++++++++++++++++++++++++++++----------- 1 file changed, 65 insertions(+), 22 deletions(-) (limited to 'net') diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c index 33d053d63407..9d68dd86023c 100644 --- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -154,6 +154,7 @@ struct sock *bt_sock_alloc(struct net *net, struct socket *sock, sock_init_data(sock, sk); INIT_LIST_HEAD(&bt_sk(sk)->accept_q); + spin_lock_init(&bt_sk(sk)->accept_q_lock); sock_reset_flag(sk, SOCK_ZAPPED); @@ -214,6 +215,7 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh) { const struct cred *old_cred; struct pid *old_pid; + struct bt_sock *par = bt_sk(parent); BT_DBG("parent %p, sk %p", parent, sk); @@ -224,9 +226,13 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh) else lock_sock_nested(sk, SINGLE_DEPTH_NESTING); - list_add_tail(&bt_sk(sk)->accept_q, &bt_sk(parent)->accept_q); bt_sk(sk)->parent = parent; + spin_lock_bh(&par->accept_q_lock); + list_add_tail(&bt_sk(sk)->accept_q, &par->accept_q); + sk_acceptq_added(parent); + spin_unlock_bh(&par->accept_q_lock); + /* Copy credentials from parent since for incoming connections the * socket is allocated by the kernel. */ @@ -244,8 +250,6 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh) bh_unlock_sock(sk); else release_sock(sk); - - sk_acceptq_added(parent); } EXPORT_SYMBOL(bt_accept_enqueue); @@ -254,45 +258,72 @@ EXPORT_SYMBOL(bt_accept_enqueue); */ void bt_accept_unlink(struct sock *sk) { + struct sock *parent = bt_sk(sk)->parent; + BT_DBG("sk %p state %d", sk, sk->sk_state); + spin_lock_bh(&bt_sk(parent)->accept_q_lock); list_del_init(&bt_sk(sk)->accept_q); - sk_acceptq_removed(bt_sk(sk)->parent); + sk_acceptq_removed(parent); + spin_unlock_bh(&bt_sk(parent)->accept_q_lock); bt_sk(sk)->parent = NULL; sock_put(sk); } EXPORT_SYMBOL(bt_accept_unlink); +static struct sock *bt_accept_get(struct sock *parent, struct sock *sk) +{ + struct bt_sock *bt = bt_sk(parent); + struct sock *next = NULL; + + /* accept_q is modified from child teardown paths too, so take a + * temporary reference before dropping the queue lock. + */ + spin_lock_bh(&bt->accept_q_lock); + + if (sk) { + if (bt_sk(sk)->parent != parent) + goto out; + + if (!list_is_last(&bt_sk(sk)->accept_q, &bt->accept_q)) { + next = &list_next_entry(bt_sk(sk), accept_q)->sk; + sock_hold(next); + } + } else if (!list_empty(&bt->accept_q)) { + next = &list_first_entry(&bt->accept_q, + struct bt_sock, accept_q)->sk; + sock_hold(next); + } + +out: + spin_unlock_bh(&bt->accept_q_lock); + return next; +} + struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock) { - struct bt_sock *s, *n; - struct sock *sk; + struct sock *sk, *next; BT_DBG("parent %p", parent); restart: - list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) { - sk = (struct sock *)s; - + for (sk = bt_accept_get(parent, NULL); sk; sk = next) { /* Prevent early freeing of sk due to unlink and sock_kill */ - sock_hold(sk); lock_sock(sk); /* Check sk has not already been unlinked via * bt_accept_unlink() due to serialisation caused by sk locking */ - if (!bt_sk(sk)->parent) { + if (bt_sk(sk)->parent != parent) { BT_DBG("sk %p, already unlinked", sk); release_sock(sk); sock_put(sk); - /* Restart the loop as sk is no longer in the list - * and also avoid a potential infinite loop because - * list_for_each_entry_safe() is not thread safe. - */ goto restart; } + next = bt_accept_get(parent, sk); + /* sk is safely in the parent list so reduce reference count */ sock_put(sk); @@ -310,6 +341,8 @@ restart: sock_graft(sk, newsock); release_sock(sk); + if (next) + sock_put(next); return sk; } @@ -518,18 +551,28 @@ EXPORT_SYMBOL(bt_sock_stream_recvmsg); static inline __poll_t bt_accept_poll(struct sock *parent) { - struct bt_sock *s, *n; + struct bt_sock *bt = bt_sk(parent); + struct bt_sock *s; struct sock *sk; + __poll_t mask = 0; + + spin_lock_bh(&bt->accept_q_lock); + list_for_each_entry(s, &bt->accept_q, accept_q) { + int state; - list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) { sk = (struct sock *)s; - if (sk->sk_state == BT_CONNECTED || - (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags) && - sk->sk_state == BT_CONNECT2)) - return EPOLLIN | EPOLLRDNORM; + state = READ_ONCE(sk->sk_state); + + if (state == BT_CONNECTED || + (test_bit(BT_SK_DEFER_SETUP, &bt->flags) && + state == BT_CONNECT2)) { + mask = EPOLLIN | EPOLLRDNORM; + break; + } } + spin_unlock_bh(&bt->accept_q_lock); - return 0; + return mask; } __poll_t bt_sock_poll(struct file *file, struct socket *sock, -- cgit v1.2.3 From 3374ef8cf99368a40f7efd51a2a375a4c5dc6f0d Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Mon, 11 May 2026 08:26:41 -0400 Subject: Bluetooth: L2CAP: ecred_reconfigure: send packed pdu, not stack pointer Commit 1c08108f3014 ("Bluetooth: L2CAP: Avoid -Wflex-array-member-not-at-end warnings") converted the on-stack request PDU in l2cap_ecred_reconfigure() from an explicit packed struct to DEFINE_RAW_FLEX(), but did not adjust the size and source-pointer arguments to l2cap_send_cmd(): - struct { - struct l2cap_ecred_reconf_req req; - __le16 scid; - } pdu; + DEFINE_RAW_FLEX(struct l2cap_ecred_reconf_req, pdu, scid, 1); ... l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ, sizeof(pdu), &pdu); After the conversion, DEFINE_RAW_FLEX() expands to declare an anonymous union pdu_u plus a local pointer "pdu" pointing at it. Therefore: - sizeof(pdu) is now sizeof(struct l2cap_ecred_reconf_req *) = 8 on 64-bit (4 on 32-bit), not the 6 bytes of (mtu, mps, scid[1]). - &pdu is the address of the local pointer's stack storage, not the address of the request payload. l2cap_send_cmd() forwards (data, count) to l2cap_build_cmd(), which calls skb_put_data(skb, data, count). The L2CAP_ECRED_RECONFIGURE_REQ packet body therefore contains 8 bytes copied from the kernel stack starting at &pdu -- the 8 bytes overlap the pdu pointer's value, leaking a kernel stack address to the paired Bluetooth peer. The intended (mtu, mps, scid) fields are not transmitted at all, so the peer rejects the request as malformed and the L2CAP_ECRED_RECONFIGURE feature itself has been broken for the local-side initiator since the introducing commit landed. The sibling site l2cap_ecred_conn_req() in the same commit was converted correctly (sizeof(*pdu) + len, pdu); only this site was missed. Restore the original semantics: pass the full flex-struct size via struct_size(pdu, scid, 1) and the pdu pointer (the struct address) as the source. Validated on a stock 7.0-based host kernel via the real call path: setsockopt(SOL_BLUETOOTH, BT_RCVMTU, ...) on a BT_CONNECTED L2CAP_MODE_EXT_FLOWCTL socket emits an L2CAP_ECRED_RECONFIGURE_REQ whose body is 8 bytes (the on-stack pdu local's value) rather than the expected 6. Three captures from fresh socket / fresh hciemu peer on the same host -- low bytes vary per call, high 0xffff confirms a kernel virtual address (KASLR-randomised stack slot, not a fixed string): RECONF_REQ body (ident=0x02 len=8): 42 fb 54 af 0e ca ff ff RECONF_REQ body (ident=0x02 len=8): 52 3d 2e af 0e ca ff ff RECONF_REQ body (ident=0x02 len=8): b2 fc 5b af 0e ca ff ff After this patch the body is 6 bytes carrying the expected little-endian (mtu, mps, scid). Cc: stable@vger.kernel.org Fixes: 1c08108f3014 ("Bluetooth: L2CAP: Avoid -Wflex-array-member-not-at-end warnings") Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/l2cap_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 7701528f1167..fdccd62ccca8 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -7274,7 +7274,7 @@ static void l2cap_ecred_reconfigure(struct l2cap_chan *chan) chan->ident = l2cap_get_ident(conn); l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ, - sizeof(pdu), &pdu); + struct_size(pdu, scid, 1), pdu); } int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu) -- cgit v1.2.3 From 9cd3f16c320bfdadd4509358122368deb56a5741 Mon Sep 17 00:00:00 2001 From: Ruide Cao Date: Wed, 13 May 2026 11:58:15 +0800 Subject: batman-adv: fix fragment reassembly length accounting batman-adv keeps a running payload length for queued fragments and uses it to validate a fragment chain before reassembly. That accounting currently allows the accumulated fragment length to be truncated during updates. As a result, malformed fragment chains can bypass the intended validation and drive reassembly with inconsistent length state, leading to a local denial of service. Fix the accounting by storing the accumulated length in a length-typed field and rejecting update overflows before the existing validation logic runs. The fix was verified against the original reproducer and against valid fragment reassembly paths. Fixes: 610bfc6bc99b ("batman-adv: Receive fragmented packets and merge") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Ruide Cao Tested-by: Ren Wei Signed-off-by: Ren Wei Signed-off-by: Sven Eckelmann --- net/batman-adv/fragmentation.c | 23 +++++++++++++++++------ net/batman-adv/types.h | 2 +- 2 files changed, 18 insertions(+), 7 deletions(-) (limited to 'net') diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index f4e45cc25816..1152c2ce0c1e 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -80,9 +81,9 @@ void batadv_frag_purge_orig(struct batadv_orig_node *orig_node, * * Return: the maximum size of payload that can be fragmented. */ -static int batadv_frag_size_limit(void) +static size_t batadv_frag_size_limit(void) { - int limit = BATADV_FRAG_MAX_FRAG_SIZE; + size_t limit = BATADV_FRAG_MAX_FRAG_SIZE; limit -= sizeof(struct batadv_frag_packet); limit *= BATADV_FRAG_MAX_FRAGMENTS; @@ -143,7 +144,9 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node, struct batadv_frag_packet *frag_packet; u8 bucket; u16 seqno, hdr_size = sizeof(struct batadv_frag_packet); + bool overflow = false; bool ret = false; + size_t data_len; /* Linearize packet to avoid linearizing 16 packets in a row when doing * the later merge. Non-linear merge should be added to remove this @@ -153,6 +156,7 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node, goto err; frag_packet = (struct batadv_frag_packet *)skb->data; + data_len = skb->len - hdr_size; seqno = ntohs(frag_packet->seqno); bucket = seqno % BATADV_FRAG_BUFFER_COUNT; @@ -171,7 +175,7 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node, spin_lock_bh(&chain->lock); if (batadv_frag_init_chain(chain, seqno)) { hlist_add_head(&frag_entry_new->list, &chain->fragment_list); - chain->size = skb->len - hdr_size; + chain->size = data_len; chain->timestamp = jiffies; chain->total_size = ntohs(frag_packet->total_size); ret = true; @@ -188,7 +192,11 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node, if (frag_entry_curr->no < frag_entry_new->no) { hlist_add_before(&frag_entry_new->list, &frag_entry_curr->list); - chain->size += skb->len - hdr_size; + + if (check_add_overflow(chain->size, data_len, + &chain->size)) + overflow = true; + chain->timestamp = jiffies; ret = true; goto out; @@ -201,13 +209,16 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node, /* Reached the end of the list, so insert after 'frag_entry_last'. */ if (likely(frag_entry_last)) { hlist_add_behind(&frag_entry_new->list, &frag_entry_last->list); - chain->size += skb->len - hdr_size; + + if (check_add_overflow(chain->size, data_len, &chain->size)) + overflow = true; + chain->timestamp = jiffies; ret = true; } out: - if (chain->size > batadv_frag_size_limit() || + if (overflow || chain->size > batadv_frag_size_limit() || chain->total_size != ntohs(frag_packet->total_size) || chain->total_size > batadv_frag_size_limit()) { /* Clear chain if total size of either the list or the packet diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 739439e2b235..c8c3e8064f00 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -301,7 +301,7 @@ struct batadv_frag_table_entry { u16 seqno; /** @size: accumulated size of packets in list */ - u16 size; + size_t size; /** @total_size: expected size of the assembled packet */ u16 total_size; -- cgit v1.2.3 From a340a51ed801eab7bb454150c226323b865263cc Mon Sep 17 00:00:00 2001 From: Ruijie Li Date: Thu, 14 May 2026 16:13:25 +0800 Subject: batman-adv: clear current gateway during teardown batadv_gw_node_free() removes the gateway list entries during mesh teardown, but it does not clear the currently selected gateway. This leaves stale gateway state behind across cleanup and can break a later mesh recreation. Clear bat_priv->gw.curr_gw before walking the gateway list so the selected gateway reference is dropped as part of teardown. Fixes: 2265c1410864 ("batman-adv: gateway election code refactoring") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Ruijie Li Signed-off-by: Zhanpeng Li Signed-off-by: Ren Wei Signed-off-by: Sven Eckelmann --- net/batman-adv/gateway_client.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net') diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index 51e9c081a2a4..a9d0346e8332 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -478,10 +478,14 @@ void batadv_gw_node_delete(struct batadv_priv *bat_priv, */ void batadv_gw_node_free(struct batadv_priv *bat_priv) { + struct batadv_gw_node *curr_gw; struct batadv_gw_node *gw_node; struct hlist_node *node_tmp; spin_lock_bh(&bat_priv->gw.list_lock); + curr_gw = rcu_replace_pointer(bat_priv->gw.curr_gw, NULL, true); + batadv_gw_node_put(curr_gw); + hlist_for_each_entry_safe(gw_node, node_tmp, &bat_priv->gw.gateway_list, list) { hlist_del_init_rcu(&gw_node->list); -- cgit v1.2.3 From 2d8826a2d3657cea66fb0370f9e521575a673871 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Wed, 13 May 2026 09:01:34 +0200 Subject: batman-adv: dat: handle forward allocation error batadv_dat_forward_data() calls pskb_copy_for_clone() to duplicate an skb for each DHT candidate, but does not check the return value before passing it to batadv_send_skb_prepare_unicast_4addr(). That function dereferences the skb unconditionally, so a failed allocation triggers a NULL pointer dereference. Skip forwarding to the current DHT candidate on allocation failure. Cc: stable@kernel.org Fixes: 785ea1144182 ("batman-adv: Distributed ARP Table - create DHT helper functions") Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Reviewed-by: Yuan Tan Signed-off-by: Sven Eckelmann --- net/batman-adv/distributed-arp-table.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net') diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 3efc4cf50b46..0a8bd95e2f99 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -696,6 +696,9 @@ static bool batadv_dat_forward_data(struct batadv_priv *bat_priv, goto free_orig; tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC); + if (!tmp_skb) + goto free_neigh; + if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb, cand[i].orig_node, packet_subtype)) { -- cgit v1.2.3 From 6c65cf23d4c6170fcf5714c32aa64689718cb142 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Wed, 13 May 2026 09:01:35 +0200 Subject: batman-adv: tp_meter: avoid use of uninit sender vars batadv_tp_recv_ack() and batadv_tp_stop() are only valid for tp_vars in the BATADV_TP_SENDER role. When called with a BATADV_TP_RECEIVER role, it proceeds to read sender-only members that were never initialized, leading to undefined behavior. This can be triggered when a node that is currently acting as a receiver in an ongoing tp_meter session receives a malicious ACK packet. Guard against this by checking tp_vars->role immediately after the lookup and bailing out if it is not BATADV_TP_SENDER, before any of those members are accessed. Cc: stable@kernel.org Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation") Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Reviewed-by: Yuan Tan Signed-off-by: Sven Eckelmann --- net/batman-adv/tp_meter.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index ca6c3f6374bc..a3593d104caa 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -664,6 +664,9 @@ static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, if (unlikely(!tp_vars)) return; + if (unlikely(tp_vars->role != BATADV_TP_SENDER)) + goto out; + if (unlikely(atomic_read(&tp_vars->sending) == 0)) goto out; @@ -1101,12 +1104,16 @@ void batadv_tp_stop(struct batadv_priv *bat_priv, const u8 *dst, if (!tp_vars) { batadv_dbg(BATADV_DBG_TP_METER, bat_priv, "Meter: trying to interrupt an already over connection\n"); - goto out; + goto out_put_orig_node; } + if (unlikely(tp_vars->role != BATADV_TP_SENDER)) + goto out_put_tp_vars; + batadv_tp_sender_shutdown(tp_vars, return_value); +out_put_tp_vars: batadv_tp_vars_put(tp_vars); -out: +out_put_orig_node: batadv_orig_node_put(orig_node); } -- cgit v1.2.3 From d2bfdbb69cf87676981b1043010b6224d84c6d3a Mon Sep 17 00:00:00 2001 From: Maoyi Xie Date: Tue, 12 May 2026 22:28:07 +0800 Subject: rds_tcp: close NULL deref window in rds_tcp_set_callbacks rds_tcp_set_callbacks() links a new rds_tcp_connection onto rds_tcp_tc_list under rds_tcp_tc_list_lock. It releases the lock, then assigns tc->t_sock = sock outside the lock. rds_tcp_tc_info() and rds6_tcp_tc_info() walk rds_tcp_tc_list under the same lock. Both dereference tc->t_sock->sk without a NULL check. A reader can acquire rds_tcp_tc_list_lock between the writer's spin_unlock and the t_sock store. It then sees a list entry whose t_sock is NULL. The dereference of tc->t_sock->sk is a NULL access. Move tc->t_sock = sock inside rds_tcp_tc_list_lock, before list_add_tail. A reader holding the lock then observes the linkage and the t_sock store together. The restore path is safe. rds_tcp_restore_callbacks() does list_del_init inside the lock. The matching tc->t_sock = NULL after unlink is harmless to readers holding the lock. Fixes: 70041088e3b9 ("RDS: Add TCP transport to RDS") Suggested-by: Simon Horman Signed-off-by: Maoyi Xie Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20260512142807.1855619-1-maoyi.xie@ntu.edu.sg Signed-off-by: Jakub Kicinski --- net/rds/tcp.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/rds/tcp.c b/net/rds/tcp.c index 654e23d13e3d..5830b31a1f37 100644 --- a/net/rds/tcp.c +++ b/net/rds/tcp.c @@ -198,8 +198,13 @@ void rds_tcp_set_callbacks(struct socket *sock, struct rds_conn_path *cp) rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc); write_lock_bh(&sock->sk->sk_callback_lock); - /* done under the callback_lock to serialize with write_space */ + /* done under the callback_lock to serialize with write_space. + * Set t_sock inside rds_tcp_tc_list_lock so readers walking + * rds_tcp_tc_list under the same lock cannot observe an + * entry whose t_sock is NULL. + */ spin_lock(&rds_tcp_tc_list_lock); + tc->t_sock = sock; list_add_tail(&tc->t_list_item, &rds_tcp_tc_list); #if IS_ENABLED(CONFIG_IPV6) rds6_tcp_tc_count++; @@ -211,8 +216,6 @@ void rds_tcp_set_callbacks(struct socket *sock, struct rds_conn_path *cp) /* accepted sockets need our listen data ready undone */ if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready) sock->sk->sk_data_ready = sock->sk->sk_user_data; - - tc->t_sock = sock; if (!tc->t_rtn) tc->t_rtn = net_generic(sock_net(sock->sk), rds_tcp_netid); tc->t_cpath = cp; -- cgit v1.2.3 From f84eca5817390257cef78013d0112481c503b4a3 Mon Sep 17 00:00:00 2001 From: William Bowling Date: Wed, 13 May 2026 04:16:35 +0000 Subject: net: skbuff: preserve shared-frag marker during coalescing skb_try_coalesce() can attach paged frags from @from to @to. If @from has SKBFL_SHARED_FRAG set, the resulting @to skb can contain the same externally-owned or page-cache-backed frags, but the shared-frag marker is currently lost. That breaks the invariant relied on by later in-place writers. In particular, ESP input checks skb_has_shared_frag() before deciding whether an uncloned nonlinear skb can skip skb_cow_data(). If TCP receive coalescing has moved shared frags into an unmarked skb, ESP can see skb_has_shared_frag() as false and decrypt in place over page-cache backed frags. Propagate SKBFL_SHARED_FRAG when skb_try_coalesce() transfers paged frags. The tailroom copy path does not need the marker because it copies bytes into @to's linear data rather than transferring frag descriptors. Fixes: cef401de7be8 ("net: fix possible wrong checksum generation") Fixes: f4c50a4034e6 ("xfrm: esp: avoid in-place decrypt on shared skb frags") Signed-off-by: William Bowling Reviewed-by: Eric Dumazet Tested-by: Jiayuan Chen Link: https://patch.msgid.link/20260513041635.1289541-1-vakzz@zellic.io Signed-off-by: Jakub Kicinski --- net/core/skbuff.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 7dad68e3b518..9c4e8d331d6d 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -6200,6 +6200,8 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, from_shinfo->frags, from_shinfo->nr_frags * sizeof(skb_frag_t)); to_shinfo->nr_frags += from_shinfo->nr_frags; + if (from_shinfo->nr_frags) + to_shinfo->flags |= from_shinfo->flags & SKBFL_SHARED_FRAG; if (!skb_cloned(from)) from_shinfo->nr_frags = 0; -- cgit v1.2.3 From f508262ae9f21fe0e6c0749948b9dc7dd5a62a70 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 13 May 2026 08:58:25 -0400 Subject: tls: Preserve sk_err across recvmsg() when data has been copied The sk_err check in tls_rx_rec_wait() consumes the error via sock_error(), which clears sk_err atomically. When the caller (tls_sw_recvmsg, tls_sw_splice_read, or tls_sw_read_sock) already has bytes copied to userspace, it returns those bytes and discards the error from this call. sk_err is now zero on the socket, so the next read syscall observes only RCV_SHUTDOWN and reports a clean EOF instead of the actual error (typically -ECONNRESET). The race is reachable when tls_read_flush_backlog()'s periodic sk_flush_backlog() triggers tcp_reset() in the middle of a multi-record read. Pass a has_copied flag to tls_rx_rec_wait(). When has_copied is false, consume sk_err via sock_error() as before. When has_copied is true, report the error from READ_ONCE() but leave sk_err set: the caller returns the byte count and discards the err from this call, and the next read syscall surfaces the preserved sk_err. This mirrors the tcp_recvmsg() preserve-and-surface pattern. The decrypt-abort path is unaffected: tls_err_abort() raises sk_err to EBADMSG after tls_rx_rec_wait() returns, and nothing on the caller's return path consumes it, so the EBADMSG surfaces on the next read. tls_sw_splice_read() passes has_copied=false: it processes one record per call, so no bytes have been copied within the function when tls_rx_rec_wait() runs. A reset that arrives between iterations of splice_direct_to_actor() (the sendfile() path) is still consumed by sock_error() in the later call, and the outer loop returns the prior iterations' byte count and drops the error. tcp_splice_read() exhibits the same pattern at the iteration boundary; addressing it belongs at the splice_direct_to_actor() layer and is out of scope here. Fixes: c46b01839f7a ("tls: rx: periodically flush socket backlog") Suggested-by: Jakub Kicinski Signed-off-by: Chuck Lever Link: https://patch.msgid.link/20260513125825.205189-1-cel@kernel.org Signed-off-by: Jakub Kicinski --- net/tls/tls_sw.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) (limited to 'net') diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 3bfdaf5e64f5..964ebc268ee4 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1366,9 +1366,14 @@ unlock: mutex_unlock(&tls_ctx->tx_lock); } +/* When has_copied is true the caller has already moved bytes to + * userspace. Report sk_err but leave it set so the next read + * surfaces it instead of a spurious EOF, otherwise sk_err is + * consumed via sock_error(). + */ static int tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock, - bool released) + bool released, bool has_copied) { struct tls_context *tls_ctx = tls_get_ctx(sk); struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx); @@ -1386,8 +1391,11 @@ tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock, if (!sk_psock_queue_empty(psock)) return 0; - if (sk->sk_err) + if (sk->sk_err) { + if (has_copied) + return -READ_ONCE(sk->sk_err); return sock_error(sk); + } if (ret < 0) return ret; @@ -1423,7 +1431,7 @@ tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock, } if (unlikely(!tls_strp_msg_load(&ctx->strp, released))) - return tls_rx_rec_wait(sk, psock, nonblock, false); + return tls_rx_rec_wait(sk, psock, nonblock, false, has_copied); return 1; } @@ -2110,7 +2118,7 @@ int tls_sw_recvmsg(struct sock *sk, int to_decrypt, chunk; err = tls_rx_rec_wait(sk, psock, flags & MSG_DONTWAIT, - released); + released, !!(decrypted + copied)); if (err <= 0) { if (psock) { chunk = sk_msg_recvmsg(sk, psock, msg, len, @@ -2297,7 +2305,7 @@ ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos, struct tls_decrypt_arg darg; err = tls_rx_rec_wait(sk, NULL, flags & SPLICE_F_NONBLOCK, - true); + true, false); if (err <= 0) goto splice_read_end; @@ -2383,7 +2391,7 @@ int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc, } else { struct tls_decrypt_arg darg; - err = tls_rx_rec_wait(sk, NULL, true, released); + err = tls_rx_rec_wait(sk, NULL, true, released, !!copied); if (err <= 0) goto read_sock_end; -- cgit v1.2.3 From bc62216dc8e221e3781afa14430f45208bfa9af9 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Wed, 13 May 2026 09:01:36 +0200 Subject: batman-adv: frag: disallow unicast fragment in fragment batadv_frag_skb_buffer() is called by batadv_batman_skb_recv() when a BATADV_UNICAST_FRAG packet is received. Once all fragments are collected and the packet is reassembled, batadv_recv_frag_packet() calls batadv_batman_skb_recv() again to process the defragmented payload. A malicious sender can craft a BATADV_UNICAST_FRAG packet whose reassembled payload is itself a BATADV_UNICAST_FRAG packet (matryoshka-style nesting). Each nesting level recurses through batadv_batman_skb_recv() without bound, growing the kernel stack until it is exhausted. Since refragmentation or fragments in fragments are not actually allowed, discard all packets which are still BATADV_UNICAST_FRAG packets after the defragmentation process. Cc: stable@kernel.org Fixes: 610bfc6bc99b ("batman-adv: Receive fragmented packets and merge") Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Reviewed-by: Yuan Tan Signed-off-by: Sven Eckelmann --- net/batman-adv/fragmentation.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'net') diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 1152c2ce0c1e..4a594aa2ebf6 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -304,6 +304,31 @@ free: return skb_out; } +/** + * batadv_skb_is_frag() - check if newly merged skb is gain a unicast packet + * @skb: newly merged skb + * + * Return: if newly skb is of type BATADV_UNICAST_FRAG + */ +static bool batadv_skb_is_frag(struct sk_buff *skb) +{ + struct batadv_ogm_packet *batadv_ogm_packet; + + /* packet should hold at least type and version */ + if (unlikely(!pskb_may_pull(skb, 2))) + return false; + + batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data; + + if (batadv_ogm_packet->version != BATADV_COMPAT_VERSION) + return false; + + if (batadv_ogm_packet->packet_type != BATADV_UNICAST_FRAG) + return false; + + return true; +} + /** * batadv_frag_skb_buffer() - buffer fragment for later merge * @skb: skb to buffer @@ -337,6 +362,16 @@ bool batadv_frag_skb_buffer(struct sk_buff **skb, if (!skb_out) goto out_err; + /* fragment in fragment is not allowed. otherwise it is possible + * to exhaust the stack when receiving a matryoshka-style + * "fragments in a fragment packet" + */ + if (batadv_skb_is_frag(skb_out)) { + kfree_skb(skb_out); + skb_out = NULL; + goto out_err; + } + out: ret = true; out_err: -- cgit v1.2.3 From d5487249a81ea658717614009c8f46acc5b7101a Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Wed, 13 May 2026 10:43:54 +0200 Subject: batman-adv: tp_meter: directly shut down timer on cleanup batadv_tp_sender_cleanup() was calling timer_delete_sync() followed by timer_delete() to guard against the timer handler re-arming itself between the two calls. This double-deletion hack relied on the sending status being set to 0 to suppress re-arming. Replace both calls with a single timer_shutdown_sync(). This function both waits for any running timer callback to complete (like timer_delete_sync()) and permanently disarms the timer so it cannot be re-armed afterwards, making re-arming prevention unconditional and self-documenting. The re-arming property is also required because otherwise: 1. context 0 (batadv_tp_recv_ack()) checks in batadv_tp_reset_sender_timer() if sending is still 1 -> it is 2. context 1 changes in batadv_tp_sender_shutdown() sending to 0 and in this process forces the kthread to stop timer in batadv_tp_sender_cleanup() 3. context 0 continues in batadv_tp_reset_sender_timer() and rearms the timer -> but the reference for it is already gone Cc: stable@kernel.org Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation") Signed-off-by: Sven Eckelmann --- net/batman-adv/tp_meter.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'net') diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index a3593d104caa..1fd1526059d8 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -401,13 +401,7 @@ static void batadv_tp_sender_cleanup(struct batadv_tp_vars *tp_vars) batadv_tp_list_detach(tp_vars); /* kill the timer and remove its reference */ - timer_delete_sync(&tp_vars->timer); - /* the worker might have rearmed itself therefore we kill it again. Note - * that if the worker should run again before invoking the following - * timer_delete(), it would not re-arm itself once again because the status - * is OFF now - */ - timer_delete(&tp_vars->timer); + timer_shutdown_sync(&tp_vars->timer); batadv_tp_vars_put(tp_vars); } -- cgit v1.2.3 From 915fab69823a14c170dbaa3b41978768e0fe62fc Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Tue, 12 May 2026 16:51:14 -0400 Subject: ipv4: raw: reject IP_HDRINCL packets with ihl < 5 raw_send_hdrinc() validates that the caller-supplied IPv4 header fits within the message length: iphlen = iph->ihl * 4; err = -EINVAL; if (iphlen > length) goto error_free; if (iphlen >= sizeof(*iph)) { /* fix up saddr, tot_len, id, csum, transport_header */ } It does not, however, reject ihl < 5. For such a packet the "if (iphlen >= sizeof(*iph))" branch is skipped, leaving the crafted iphdr untouched, but the packet is still handed to __ip_local_out() and onward. Downstream consumers that read iph->ihl assume a sane value: net/ipv4/ah4.c:ah_output() in particular subtracts sizeof(struct iphdr) from top_iph->ihl * 4 and passes the (signed-int-negative, then cast to size_t) result to memcpy(), producing an OOB access of length close to SIZE_MAX and a host kernel panic. An IPv4 header with ihl < 5 is malformed by definition (RFC 791: "Internet Header Length is the length of the internet header in 32 bit words ... Note that the minimum value for a correct header is 5."). The kernel should not be willing to inject such a packet into its own output path. Reject "iphlen < sizeof(*iph)" alongside the existing "iphlen > length" check. This matches the principle that locally constructed packets that re-enter the IP stack must pass the same basic sanity tests that a foreign packet would be subjected to. Once this lands, the "if (iphlen >= sizeof(*iph))" wrapper around the fixup branch becomes redundant; left in place to keep the patch minimal and backport-friendly. A follow-up can unwrap it. Note that commit 86f4c90a1c5c ("ipv4, ipv6: ensure raw socket message is big enough to hold an IP header") ensures the message buffer is large enough to hold an iphdr, but does not constrain the self-reported iph->ihl. Reachability: the malformed packet source is any caller with CAP_NET_RAW, including an unprivileged process in a user+net namespace on a kernel with CONFIG_USER_NS=y. The reproduced AH crash also requires a matching xfrm AH policy on the outgoing route; a container granted CAP_NET_ADMIN can install that state and policy in its netns. Loopback bypasses xfrm_output, so the trigger uses a real netdev. Reproduced on UML + KASAN: kernel-mode fault at addr 0x0 with memcpy_orig at the crash site. Same shape reproduces inside a rootless Docker container with --cap-add NET_ADMIN on a stock distro kernel. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Suggested-by: Herbert Xu Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/77ec2b5e8111961c2c39883c92e8aa2709039c17.1778614451.git.michael.bommarito@gmail.com Signed-off-by: Jakub Kicinski --- net/ipv4/raw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c index 5aaf9c62c8e1..68e88cb3e55c 100644 --- a/net/ipv4/raw.c +++ b/net/ipv4/raw.c @@ -391,7 +391,7 @@ static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4, * in, reject the frame as invalid */ err = -EINVAL; - if (iphlen > length) + if (iphlen > length || iphlen < sizeof(*iph)) goto error_free; if (iphlen >= sizeof(*iph)) { -- cgit v1.2.3 From ae38d9179190a956e2a87a69ef1dd6f451b51c4d Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Thu, 14 May 2026 11:29:48 +0200 Subject: vsock/virtio: fix zerocopy completion for multi-skb sends When a large message is fragmented into multiple skbs, the zerocopy uarg is only allocated and attached to the last skb in the loop. Non-final skbs carry pinned user pages with no completion tracking, so the kernel has no way to notify userspace when those pages are safe to reuse. If the loop breaks early the uarg is never allocated at all, leaking pinned pages with no completion notification. Fix this by following the approach used by TCP: allocate the zerocopy uarg (if not provided by the caller) before the send loop and attach it to every skb via skb_zcopy_set(), which takes a reference per skb. Each skb's completion properly decrements the refcount, and the notification only fires after the last skb is freed. On failure, if no data was sent, the uarg is cleanly aborted via net_zcopy_put_abort(). This issue was initially discovered by sashiko while reviewing commit 1cb36e252211 ("vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting") but was pre-existing. Fixes: 581512a6dc93 ("vsock/virtio: MSG_ZEROCOPY flag support") Closes: https://sashiko.dev/#/patchset/20260420132051.217589-1-sgarzare%40redhat.com Reported-by: Maher Azzouzi Signed-off-by: Stefano Garzarella Acked-by: Michael S. Tsirkin Acked-by: Arseniy Krasnov Link: https://patch.msgid.link/20260514092948.268720-1-sgarzare@redhat.com Signed-off-by: Jakub Kicinski --- net/vmw_vsock/virtio_transport_common.c | 83 ++++++++++++++------------------- 1 file changed, 34 insertions(+), 49 deletions(-) (limited to 'net') diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 989cc252d3d3..1e3409d28164 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -70,34 +70,6 @@ static bool virtio_transport_can_zcopy(const struct virtio_transport *t_ops, return true; } -static int virtio_transport_init_zcopy_skb(struct vsock_sock *vsk, - struct sk_buff *skb, - struct msghdr *msg, - size_t pkt_len, - bool zerocopy) -{ - struct ubuf_info *uarg; - - if (msg->msg_ubuf) { - uarg = msg->msg_ubuf; - net_zcopy_get(uarg); - } else { - struct ubuf_info_msgzc *uarg_zc; - - uarg = msg_zerocopy_realloc(sk_vsock(vsk), - pkt_len, NULL, false); - if (!uarg) - return -1; - - uarg_zc = uarg_to_msgzc(uarg); - uarg_zc->zerocopy = zerocopy ? 1 : 0; - } - - skb_zcopy_init(skb, uarg); - - return 0; -} - static int virtio_transport_fill_skb(struct sk_buff *skb, struct virtio_vsock_pkt_info *info, size_t len, @@ -317,8 +289,10 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, u32 src_cid, src_port, dst_cid, dst_port; const struct virtio_transport *t_ops; struct virtio_vsock_sock *vvs; + struct ubuf_info *uarg = NULL; u32 pkt_len = info->pkt_len; bool can_zcopy = false; + bool have_uref = false; u32 rest_len; int ret; @@ -360,6 +334,25 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, if (can_zcopy) max_skb_len = min_t(u32, VIRTIO_VSOCK_MAX_PKT_BUF_SIZE, (MAX_SKB_FRAGS * PAGE_SIZE)); + + if (info->msg->msg_flags & MSG_ZEROCOPY && + info->op == VIRTIO_VSOCK_OP_RW) { + uarg = info->msg->msg_ubuf; + + if (!uarg) { + uarg = msg_zerocopy_realloc(sk_vsock(vsk), + pkt_len, NULL, false); + if (!uarg) { + virtio_transport_put_credit(vvs, pkt_len); + return -ENOMEM; + } + + if (!can_zcopy) + uarg_to_msgzc(uarg)->zerocopy = 0; + + have_uref = true; + } + } } rest_len = pkt_len; @@ -378,27 +371,7 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, break; } - /* We process buffer part by part, allocating skb on - * each iteration. If this is last skb for this buffer - * and MSG_ZEROCOPY mode is in use - we must allocate - * completion for the current syscall. - * - * Pass pkt_len because msg iter is already consumed - * by virtio_transport_fill_skb(), so iter->count - * can not be used for RLIMIT_MEMLOCK pinned-pages - * accounting done by msg_zerocopy_realloc(). - */ - if (info->msg && info->msg->msg_flags & MSG_ZEROCOPY && - skb_len == rest_len && info->op == VIRTIO_VSOCK_OP_RW) { - if (virtio_transport_init_zcopy_skb(vsk, skb, - info->msg, - pkt_len, - can_zcopy)) { - kfree_skb(skb); - ret = -ENOMEM; - break; - } - } + skb_zcopy_set(skb, uarg, NULL); virtio_transport_inc_tx_pkt(vvs, skb); @@ -422,6 +395,18 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, virtio_transport_put_credit(vvs, rest_len); + /* msg_zerocopy_realloc() initializes the ubuf_info refcnt to 1. + * skb_zcopy_set() increases it for each skb, so we can drop that + * initial reference to keep it balanced. + */ + if (have_uref) { + if (rest_len == pkt_len) + /* No data sent, abort the notification. */ + net_zcopy_put_abort(uarg, true); + else + net_zcopy_put(uarg); + } + /* Return number of bytes, if any data has been sent. */ if (rest_len != pkt_len) ret = pkt_len - rest_len; -- cgit v1.2.3 From aaec7096f9961eb223b5b149abe9495525c205d9 Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Wed, 13 May 2026 19:38:38 -0400 Subject: net: hsr: defer node table free until after RCU readers HSR node-list and node-status generic-netlink operations run under rcu_read_lock(). They walk hsr->node_db through hsr_get_next_node() and hsr_get_node_data(), but RTM_DELLINK teardown removes the same node table with plain list_del() and frees each node immediately. That lets a generic-netlink reader hold a struct hsr_node pointer across hsr_dellink(). In a KASAN build, widening the reader window after hsr_get_next_node() obtains the node reproduces a slab-use-after-free when the reader copies node->macaddress_A; the freeing stack is hsr_del_nodes() from hsr_dellink(). Use list_del_rcu() and defer the free through the existing hsr_free_node_rcu() callback. This matches the lifetime rule used by the HSR prune paths, which already delete nodes with list_del_rcu() and call_rcu(). Fixes: b9a1e627405d ("hsr: implement dellink to clean up resources") Cc: stable@vger.kernel.org # v5.3+ Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/20260513233838.3064715-2-michael.bommarito@gmail.com Signed-off-by: Jakub Kicinski --- net/hsr/hsr_framereg.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c index 124619920d38..b514e43766ef 100644 --- a/net/hsr/hsr_framereg.c +++ b/net/hsr/hsr_framereg.c @@ -163,8 +163,8 @@ void hsr_del_nodes(struct list_head *node_db) struct hsr_node *tmp; list_for_each_entry_safe(node, tmp, node_db, mac_list) { - list_del(&node->mac_list); - hsr_free_node(node); + list_del_rcu(&node->mac_list); + call_rcu(&node->rcu_head, hsr_free_node_rcu); } } -- cgit v1.2.3 From 1afc25ae75288b3ce59e9e5a4b448bd354c9e565 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Sat, 9 May 2026 10:27:06 +0200 Subject: netfilter: nf_conntrack_helper: fix possible null deref during error log Reported by sashiko: there is a small race window. If a helper module is unloaded or a userspace-defined helper is removed, nf_conntrack_helper_unregister() sets ->helper to NULL. Handle this safely. This needs a second patch to close related race during nf_conntrack_helper_unregister(). Fixes: b20ab9cc63ca ("netfilter: nf_ct_helper: better logging for dropped packets") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_helper.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'net') diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index b594cd244fe1..17e971bd4c74 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -321,8 +321,8 @@ __printf(3, 4) void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct, const char *fmt, ...) { + const char *helper_name = "(null)"; const struct nf_conn_help *help; - const struct nf_conntrack_helper *helper; struct va_format vaf; va_list args; @@ -331,14 +331,17 @@ void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct, vaf.fmt = fmt; vaf.va = &args; - /* Called from the helper function, this call never fails */ help = nfct_help(ct); + if (help) { + const struct nf_conntrack_helper *helper; - /* rcu_read_lock()ed by nf_hook_thresh */ - helper = rcu_dereference(help->helper); + helper = rcu_dereference(help->helper); + if (helper) + helper_name = helper->name; + } nf_log_packet(nf_ct_net(ct), nf_ct_l3num(ct), 0, skb, NULL, NULL, NULL, - "nf_ct_%s: dropping packet: %pV ", helper->name, &vaf); + "helper %s dropping packet: %pV ", helper_name, &vaf); va_end(args); } -- cgit v1.2.3 From 5522d65d81a711c60a9969d37a485d48d0ad1496 Mon Sep 17 00:00:00 2001 From: Julian Anastasov Date: Sun, 10 May 2026 13:46:05 +0300 Subject: ipvs: avoid possible loop in ip_vs_dst_event on resizing Sashiko points out that unprivileged user can frequently call ip_vs_flush() or ip_vs_del_service() to trigger svc_table_changes updates that can lead to infinite loop in ip_vs_dst_event(). This can also happen if the user triggers frequent table resizing without deleting all services. We should also consider the possible effects if the user triggers many NETDEV_DOWN events. One way to solve it is to hold svc_resize_sem in ip_vs_dst_event() but this can block the dev notifier during the whole resizing process. Instead, use new rw_semaphore svc_replace_sem to protect just the svc_table replacement which is a short code section. Then hold svc_replace_sem in ip_vs_dst_event() to serialize with replacing the svc_table. As result, loop is avoided as there is no need to repeat the table walking from the start. By this way changes in svc_table_changes can happen only when all services are removed and all dev references dropped which allows us to abort the table walking. As IP_VS_WORK_SVC_NORESIZE is the flag used to stop the svc_resize_work under service_mutex, we should check only this flag often but not while under service_mutex. To remove the mutex_trylock() for service_mutex in the second phase where the resizer installs the new table after rehashing, we will avoid holding the service_mutex there. As result, the code in configuration context which is under service_mutex should access ipvs->svc_table under RCU because it can be replaced at anytime and released after a RCU grace period. As for ip_vs_zero_all(), it needs different solution as a table walker which can escape single RCU read-side critical section: to hold the svc_replace_sem to prevent table to be replaced. In ip_vs_status_show() prefer to hold svc_replace_sem to avoid many loops, just detect if the svc_table is removed. Prefer the newly attached table for the u_thresh/l_thresh checks to know when to grow/shrink while adding or deleting services because the new table size is based on the latest parameters. Link: https://sashiko.dev/#/patchset/20260505001648.360569-1-pablo%40netfilter.org Fixes: 840aac3d900d ("ipvs: use resizable hash table for services") Signed-off-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipvs/ip_vs_ctl.c | 187 +++++++++++++++++++++++++++-------------- 1 file changed, 122 insertions(+), 65 deletions(-) (limited to 'net') diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index c7c7f6a7a9f6..bd9cae44d214 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -327,18 +327,22 @@ ip_vs_use_count_dec(void) /* Service hashing: * Operation Locking order * --------------------------------------------------------------------------- - * add table service_mutex, svc_resize_sem(W) - * del table service_mutex - * move between tables svc_resize_sem(W), seqcount_t(W), bit lock - * add/del service service_mutex, bit lock + * add first table service_mutex + * attach new table service_mutex + * add/del service service_mutex, RCU, bit lock + * move between tables (rehash) svc_resize_sem(W), seqcount_t(W), bit lock + * replace old with attached svc_resize_sem(W), svc_replace_sem(W) * find service RCU, seqcount_t(R) * walk services(blocking) service_mutex, svc_resize_sem(R) * walk services(non-blocking) RCU, seqcount_t(R) + * walk services(non-blocking) svc_resize_sem(R), RCU, seqcount_t(R) + * walk services(non-blocking) svc_replace_sem(R), RCU, seqcount_t(R) + * del table service_mutex after stopped work * - * - new tables are linked/unlinked under service_mutex and svc_resize_sem - * - new table is linked on resizing and all operations can run in parallel - * in 2 tables until the new table is registered as current one - * - two contexts can modify buckets: config and table resize, both in + * - new table is attached on resizing under service_mutex and all operations + * can run in parallel in 2 tables until the new table is registered as current + * one + * - two contexts can modify buckets: config and table resize (work), both in * process context * - only table resizer can move entries, so we do not protect t->seqc[] * items with t->lock[] @@ -346,9 +350,13 @@ ip_vs_use_count_dec(void) * services are moved to new table * - move operations may disturb readers: find operation will not miss entries * but walkers may see same entry twice if they are forced to retry chains - * - walkers using cond_resched_rcu() on !PREEMPT_RCU may need to hold - * service_mutex to disallow new tables to be installed or to check + * or to walk the newly attached second table + * - walkers using cond_resched_rcu() on !PREEMPT_RCU may need to check * svc_table_changes and repeat the RCU read section if new table is installed + * - walkers may serialize with the whole resizing process (svc_resize_sem) + * to prevent seeing same service twice or just with the svc_table + * replace (svc_replace_sem) when we can see entries twice but we + * prefer to run concurrently with the rehashing. */ /* @@ -387,9 +395,16 @@ static int ip_vs_svc_hash(struct ip_vs_service *svc) /* increase its refcnt because it is referenced by the svc table */ atomic_inc(&svc->refcnt); + /* We know if new table is attached under service_mutex but rely on + * RCU to hold the old table to be freed in resizer + */ + rcu_read_lock(); + + /* This can be the old or the new table */ + t = rcu_dereference(ipvs->svc_table); + /* New entries go into recent table */ - t = rcu_dereference_protected(ipvs->svc_table, 1); - t = rcu_dereference_protected(t->new_tbl, 1); + t = rcu_dereference(t->new_tbl); if (svc->fwmark == 0) { /* @@ -410,6 +425,8 @@ static int ip_vs_svc_hash(struct ip_vs_service *svc) hlist_bl_add_head_rcu(&svc->s_list, head); hlist_bl_unlock(head); + rcu_read_unlock(); + return 1; } @@ -432,7 +449,13 @@ static int ip_vs_svc_unhash(struct ip_vs_service *svc) return 0; } - t = rcu_dereference_protected(ipvs->svc_table, 1); + /* We know if new table is attached under service_mutex but rely on + * RCU to hold the old table to be freed in resizer + */ + rcu_read_lock(); + + /* This can be the old or the new table */ + t = rcu_dereference(ipvs->svc_table); hash_key = READ_ONCE(svc->hash_key); /* We need to lock the bucket in the right table */ if (ip_vs_rht_same_table(t, hash_key)) { @@ -443,13 +466,13 @@ static int ip_vs_svc_unhash(struct ip_vs_service *svc) /* Moved to new table ? */ if (hash_key != hash_key2) { hlist_bl_unlock(head); - t = rcu_dereference_protected(t->new_tbl, 1); + t = rcu_dereference(t->new_tbl); head = t->buckets + (hash_key2 & t->mask); hlist_bl_lock(head); } } else { /* It is already moved to new table */ - t = rcu_dereference_protected(t->new_tbl, 1); + t = rcu_dereference(t->new_tbl); head = t->buckets + (hash_key & t->mask); hlist_bl_lock(head); } @@ -459,6 +482,8 @@ static int ip_vs_svc_unhash(struct ip_vs_service *svc) svc->flags &= ~IP_VS_SVC_F_HASHED; atomic_dec(&svc->refcnt); hlist_bl_unlock(head); + + rcu_read_unlock(); return 1; } @@ -666,15 +691,14 @@ static void svc_resize_work_handler(struct work_struct *work) goto unlock_sem; more_work = false; clear_bit(IP_VS_WORK_SVC_RESIZE, &ipvs->work_flags); - if (!READ_ONCE(ipvs->enable) || - test_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags)) + if (!READ_ONCE(ipvs->enable)) goto unlock_m; t = rcu_dereference_protected(ipvs->svc_table, 1); /* Do nothing if table is removed */ if (!t) goto unlock_m; - /* New table needs to be registered? BUG! */ - if (t != rcu_dereference_protected(t->new_tbl, 1)) + /* New table already attached? BUG! */ + if (t != rcu_access_pointer(t->new_tbl)) goto unlock_m; lfactor = sysctl_svc_lfactor(ipvs); @@ -691,6 +715,7 @@ static void svc_resize_work_handler(struct work_struct *work) /* Flip the table_id */ t_new->table_id = t->table_id ^ IP_VS_RHT_TABLE_ID_MASK; + /* Attach new table */ rcu_assign_pointer(t->new_tbl, t_new); /* Allow add/del to new_tbl while moving from old table */ mutex_unlock(&ipvs->service_mutex); @@ -698,8 +723,8 @@ static void svc_resize_work_handler(struct work_struct *work) ip_vs_rht_for_each_bucket(t, bucket, head) { same_bucket: if (++limit >= 16) { - if (!READ_ONCE(ipvs->enable) || - test_bit(IP_VS_WORK_SVC_NORESIZE, + /* Check if work is stopped */ + if (test_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags)) goto unlock_sem; if (resched_score >= 100) { @@ -764,16 +789,12 @@ same_bucket: goto same_bucket; } - /* Tables can be switched only under service_mutex */ - while (!mutex_trylock(&ipvs->service_mutex)) { - cond_resched(); - if (!READ_ONCE(ipvs->enable) || - test_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags)) - goto unlock_sem; - } - if (!READ_ONCE(ipvs->enable) || - test_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags)) - goto unlock_m; + /* Serialize with readers that don't like svc_table changes */ + down_write(&ipvs->svc_replace_sem); + + /* Check if work is stopped to avoid synchronize_rcu() */ + if (test_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags)) + goto unlock_repl; rcu_assign_pointer(ipvs->svc_table, t_new); /* Inform readers that new table is installed */ @@ -781,8 +802,8 @@ same_bucket: atomic_inc(&ipvs->svc_table_changes); t_free = t; -unlock_m: - mutex_unlock(&ipvs->service_mutex); +unlock_repl: + up_write(&ipvs->svc_replace_sem); unlock_sem: up_write(&ipvs->svc_resize_sem); @@ -801,6 +822,11 @@ out: test_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags)) return; queue_delayed_work(system_unbound_wq, &ipvs->svc_resize_work, 1); + return; + +unlock_m: + mutex_unlock(&ipvs->service_mutex); + goto unlock_sem; } static inline void @@ -1691,6 +1717,7 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u, struct ip_vs_pe *pe = NULL; int ret_hooks = -1; int ret = 0; + bool grow; /* increase the module use count */ if (!ip_vs_use_count_inc()) @@ -1732,16 +1759,25 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u, } #endif - t = rcu_dereference_protected(ipvs->svc_table, 1); + /* The old table can be freed, protect it with RCU */ + rcu_read_lock(); + t = rcu_dereference(ipvs->svc_table); if (!t) { int lfactor = sysctl_svc_lfactor(ipvs); int new_size = ip_vs_svc_desired_size(ipvs, NULL, lfactor); + rcu_read_unlock(); t_new = ip_vs_svc_table_alloc(ipvs, new_size, lfactor); if (!t_new) { ret = -ENOMEM; goto out_err; } + grow = false; + } else { + /* Even the currently attached new table may need to grow */ + t = rcu_dereference(t->new_tbl); + grow = ip_vs_get_num_services(ipvs) + 1 > t->u_thresh; + rcu_read_unlock(); } if (!rcu_dereference_protected(ipvs->conn_tab, 1)) { @@ -1800,6 +1836,7 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u, goto out_err; if (t_new) { + /* Add table for first time */ clear_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags); rcu_assign_pointer(ipvs->svc_table, t_new); t_new = NULL; @@ -1831,8 +1868,7 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u, ip_vs_svc_hash(svc); /* Schedule resize work */ - if (t && ip_vs_get_num_services(ipvs) > t->u_thresh && - !test_and_set_bit(IP_VS_WORK_SVC_RESIZE, &ipvs->work_flags)) + if (grow && !test_and_set_bit(IP_VS_WORK_SVC_RESIZE, &ipvs->work_flags)) queue_delayed_work(system_unbound_wq, &ipvs->svc_resize_work, 1); @@ -2054,7 +2090,6 @@ static int ip_vs_del_service(struct ip_vs_service *svc) return -EEXIST; ipvs = svc->ipvs; ip_vs_unlink_service(svc, false); - t = rcu_dereference_protected(ipvs->svc_table, 1); /* Drop the table if no more services */ ns = ip_vs_get_num_services(ipvs); @@ -2062,6 +2097,7 @@ static int ip_vs_del_service(struct ip_vs_service *svc) /* Stop the resizer and drop the tables */ set_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags); cancel_delayed_work_sync(&ipvs->svc_resize_work); + t = rcu_dereference_protected(ipvs->svc_table, 1); if (t) { rcu_assign_pointer(ipvs->svc_table, NULL); /* Inform readers that table is removed */ @@ -2075,11 +2111,19 @@ static int ip_vs_del_service(struct ip_vs_service *svc) t = p; } } - } else if (ns <= t->l_thresh && - !test_and_set_bit(IP_VS_WORK_SVC_RESIZE, - &ipvs->work_flags)) { - queue_delayed_work(system_unbound_wq, &ipvs->svc_resize_work, - 1); + } else { + bool shrink; + + rcu_read_lock(); + t = rcu_dereference(ipvs->svc_table); + /* Even the currently attached new table may need to shrink */ + t = rcu_dereference(t->new_tbl); + shrink = ns <= t->l_thresh; + rcu_read_unlock(); + if (shrink && !test_and_set_bit(IP_VS_WORK_SVC_RESIZE, + &ipvs->work_flags)) + queue_delayed_work(system_unbound_wq, + &ipvs->svc_resize_work, 1); } return 0; } @@ -2184,17 +2228,21 @@ static int ip_vs_dst_event(struct notifier_block *this, unsigned long event, struct ip_vs_service *svc; struct hlist_bl_node *e; struct ip_vs_dest *dest; - int old_gen, new_gen; + int old_gen; if (event != NETDEV_DOWN || !ipvs) return NOTIFY_DONE; IP_VS_DBG(3, "%s() dev=%s\n", __func__, dev->name); + /* Allow concurrent rehashing on resize but to avoid loop + * serialize with installing the new table. + */ + down_read(&ipvs->svc_replace_sem); + old_gen = atomic_read(&ipvs->svc_table_changes); rcu_read_lock(); -repeat: smp_rmb(); /* ipvs->svc_table and svc_table_changes */ ip_vs_rht_walk_buckets_rcu(ipvs->svc_table, head) { hlist_bl_for_each_entry_rcu(svc, e, head, s_list) { @@ -2207,17 +2255,17 @@ repeat: } resched_score++; if (resched_score >= 100) { - resched_score = 0; cond_resched_rcu(); - new_gen = atomic_read(&ipvs->svc_table_changes); - /* New table installed ? */ - if (old_gen != new_gen) { - old_gen = new_gen; - goto repeat; - } + /* Flushed? So no more dev refs */ + if (atomic_read(&ipvs->svc_table_changes) != old_gen) + goto done; + resched_score = 0; } } + +done: rcu_read_unlock(); + up_read(&ipvs->svc_replace_sem); return NOTIFY_DONE; } @@ -2244,6 +2292,10 @@ static int ip_vs_zero_all(struct netns_ipvs *ipvs) struct ip_vs_service *svc; struct hlist_bl_node *e; + /* svc_table can not be replaced (svc_replace_sem) or + * removed (service_mutex) + */ + down_read(&ipvs->svc_replace_sem); rcu_read_lock(); ip_vs_rht_walk_buckets_rcu(ipvs->svc_table, head) { @@ -2259,6 +2311,7 @@ static int ip_vs_zero_all(struct netns_ipvs *ipvs) } rcu_read_unlock(); + up_read(&ipvs->svc_replace_sem); ip_vs_zero_stats(&ipvs->tot_stats->s); return 0; @@ -3062,6 +3115,7 @@ static int ip_vs_status_show(struct seq_file *seq, void *v) u32 sum; int i; + /* Info for conns */ rcu_read_lock(); t = rcu_dereference(ipvs->conn_tab); @@ -3123,6 +3177,12 @@ repeat_conn: } after_conns: + rcu_read_unlock(); + + /* Info for services */ + down_read(&ipvs->svc_replace_sem); + rcu_read_lock(); + t = rcu_dereference(ipvs->svc_table); count = ip_vs_get_num_services(ipvs); @@ -3133,9 +3193,7 @@ after_conns: if (!count) goto after_svc; old_gen = atomic_read(&ipvs->svc_table_changes); - loops = 0; -repeat_svc: smp_rmb(); /* ipvs->svc_table and svc_table_changes */ memset(counts, 0, sizeof(counts)); ip_vs_rht_for_each_table_rcu(ipvs->svc_table, t, pt) { @@ -3157,15 +3215,10 @@ repeat_svc: if (resched_score >= 100) { resched_score = 0; cond_resched_rcu(); - new_gen = atomic_read(&ipvs->svc_table_changes); - /* New table installed ? */ - if (old_gen != new_gen) { - /* Too many changes? */ - if (++loops >= 5) - goto after_svc; - old_gen = new_gen; - goto repeat_svc; - } + /* Flushed? */ + if (atomic_read(&ipvs->svc_table_changes) != + old_gen) + goto after_svc; } counts[count]++; } @@ -3184,6 +3237,9 @@ repeat_svc: } after_svc: + rcu_read_unlock(); + up_read(&ipvs->svc_replace_sem); + seq_printf(seq, "Stats thread slots:\t%d (max %lu)\n", ipvs->est_kt_count, ipvs->est_max_threads); seq_printf(seq, "Stats chain max len:\t%d\n", ipvs->est_chain_max); @@ -3191,7 +3247,6 @@ after_svc: ipvs->est_chain_max * IPVS_EST_CHAIN_FACTOR * IPVS_EST_NTICKS); - rcu_read_unlock(); return 0; } @@ -3503,7 +3558,7 @@ __ip_vs_get_service_entries(struct netns_ipvs *ipvs, int ret = 0; lockdep_assert_held(&ipvs->svc_resize_sem); - /* All service modifications are disabled, go ahead */ + /* All svc_table modifications are disabled, go ahead */ ip_vs_rht_walk_buckets(ipvs->svc_table, head) { hlist_bl_for_each_entry(svc, e, head, s_list) { /* Only expose IPv4 entries to old interface */ @@ -3687,7 +3742,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) pr_err("length: %u != %zu\n", *len, size); return -EINVAL; } - /* Protect against table resizer moving the entries. + /* Prevent modifications to the list with services. * Try reverse locking, so that we do not hold the mutex * while waiting for semaphore. */ @@ -4029,6 +4084,7 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb, int start = cb->args[0]; int idx = 0; + /* Make sure we do not see same service twice during resize */ down_read(&ipvs->svc_resize_sem); rcu_read_lock(); ip_vs_rht_walk_buckets_safe_rcu(ipvs->svc_table, head) { @@ -5072,6 +5128,7 @@ int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs) /* Initialize service_mutex, svc_table per netns */ __mutex_init(&ipvs->service_mutex, "ipvs->service_mutex", &__ipvs_service_key); init_rwsem(&ipvs->svc_resize_sem); + init_rwsem(&ipvs->svc_replace_sem); INIT_DELAYED_WORK(&ipvs->svc_resize_work, svc_resize_work_handler); atomic_set(&ipvs->svc_table_changes, 0); RCU_INIT_POINTER(ipvs->svc_table, NULL); -- cgit v1.2.3 From 53d7fd878c28b28e03769071d1f28ef031a060ad Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Thu, 14 May 2026 10:55:10 +0200 Subject: netfilter: ipset: fix a potential dump-destroy race When dumping sets in order to create the proper order for restore, the list type of sets dumped last. Therefore internally we run the dumping loop twice: first with all non-list type of sets and skipping the list type ones and then secondly for the list type of sets. Sashiko noticed that there's a potential race between dump and destroy if in the first loop the last set was a list type of set: its pointer remains unreferenced and a concurrent destroy can free it. Fix the issue by resetting the variable holding the pointer. Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_core.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net') diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c index c5a26236a0bb..0874029cb0f2 100644 --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -1613,6 +1613,7 @@ dump_last: ((dump_type == DUMP_ALL) == !!(set->type->features & IPSET_DUMP_LAST))) { write_unlock_bh(&ip_set_ref_lock); + set = NULL; continue; } pr_debug("List set: %s\n", set->name); -- cgit v1.2.3 From b6a91f68ebfed9c38e0e9150f58a9b85da07181c Mon Sep 17 00:00:00 2001 From: Yizhou Zhao Date: Tue, 12 May 2026 01:30:41 +0800 Subject: netfilter: nft_inner: Fix IPv6 inner_thoff desync MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In nft_inner_parse_l2l3(), when processing inner IPv6 packets, ipv6_find_hdr() correctly computes the transport header offset traversing all extension headers, but the result is immediately overwritten with nhoff + sizeof(_ip6h) (40 bytes), which only accounts for the IPv6 base header. This creates a desync between inner_thoff (wrong — points to extension header start) and l4proto (correct — e.g., IPPROTO_TCP), enabling transport header forgery and potential firewall bypass. This issue affects stable versions from Linux 6.2. For comparison, the normal (non-inner) IPv6 path correctly preserves ipv6_find_hdr()'s result. Removing the incorrect overwrite ensures that ipv6_find_hdr()'s calculated transport header offset is preserved, thereby fixing the desynchronization. Fixes: 3a07327d10a0 ("netfilter: nft_inner: support for inner tunnel header matching") Cc: stable@vger.kernel.org Reported-by: Yizhou Zhao Reported-by: Yuxiang Yang Reported-by: Xuewei Feng Reported-by: Qi Li Reported-by: Ke Xu Assisted-by: GLM:5.1 Z.ai Signed-off-by: Yizhou Zhao Reviewed-by: Fernando Fernandez Mancera Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_inner.c | 1 - 1 file changed, 1 deletion(-) (limited to 'net') diff --git a/net/netfilter/nft_inner.c b/net/netfilter/nft_inner.c index 03ffb1159fc1..859aa38e333b 100644 --- a/net/netfilter/nft_inner.c +++ b/net/netfilter/nft_inner.c @@ -163,7 +163,6 @@ static int nft_inner_parse_l2l3(const struct nft_inner *priv, return -1; if (fragoff == 0) { - thoff = nhoff + sizeof(_ip6h); ctx->flags |= NFT_PAYLOAD_CTX_INNER_TH; ctx->inner_thoff = thoff; ctx->l4proto = l4proto; -- cgit v1.2.3 From 0d3a282ab5f165fc207ff49ea5b6ad8f54616bd6 Mon Sep 17 00:00:00 2001 From: Nan Li Date: Tue, 12 May 2026 16:50:01 +0800 Subject: netfilter: ipset: stop hash:* range iteration at end The following hash set variants: hash:ip,mark hash:ip,port hash:ip,port,ip hash:ip,port,net iterate IPv4 ranges with a 32-bit iterator. The iterator must stop once the last address in the requested range has been processed. Advancing it once more can move the traversal state past the end of the request, so a later retry may continue from an unintended position. Handle the iterator increment explicitly at the end of the loop and stop once the upper bound has been processed. This keeps the existing retry behaviour intact for valid ranges while preventing traversal from continuing past the original boundary. Fixes: 48596a8ddc46 ("netfilter: ipset: Fix adding an IPv4 range containing more than 2^31 addresses") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Nan Li Signed-off-by: Ren Wei Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_hash_ipmark.c | 6 +++++- net/netfilter/ipset/ip_set_hash_ipport.c | 5 ++++- net/netfilter/ipset/ip_set_hash_ipportip.c | 5 ++++- net/netfilter/ipset/ip_set_hash_ipportnet.c | 5 ++++- 4 files changed, 17 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/netfilter/ipset/ip_set_hash_ipmark.c b/net/netfilter/ipset/ip_set_hash_ipmark.c index a22ec1a6f6ec..e26ca2a370e3 100644 --- a/net/netfilter/ipset/ip_set_hash_ipmark.c +++ b/net/netfilter/ipset/ip_set_hash_ipmark.c @@ -150,7 +150,7 @@ hash_ipmark4_uadt(struct ip_set *set, struct nlattr *tb[], if (retried) ip = ntohl(h->next.ip); - for (; ip <= ip_to; ip++, i++) { + for (; ip <= ip_to; i++) { e.ip = htonl(ip); if (i > IPSET_MAX_RANGE) { hash_ipmark4_data_next(&h->next, &e); @@ -162,6 +162,10 @@ hash_ipmark4_uadt(struct ip_set *set, struct nlattr *tb[], return ret; ret = 0; + + if (ip == ip_to) + break; + ip++; } return ret; } diff --git a/net/netfilter/ipset/ip_set_hash_ipport.c b/net/netfilter/ipset/ip_set_hash_ipport.c index e977b5a9c48d..41ca24a22a02 100644 --- a/net/netfilter/ipset/ip_set_hash_ipport.c +++ b/net/netfilter/ipset/ip_set_hash_ipport.c @@ -186,7 +186,7 @@ hash_ipport4_uadt(struct ip_set *set, struct nlattr *tb[], if (retried) ip = ntohl(h->next.ip); - for (; ip <= ip_to; ip++) { + for (; ip <= ip_to;) { p = retried && ip == ntohl(h->next.ip) ? ntohs(h->next.port) : port; for (; p <= port_to; p++, i++) { @@ -203,6 +203,9 @@ hash_ipport4_uadt(struct ip_set *set, struct nlattr *tb[], ret = 0; } + if (ip == ip_to) + break; + ip++; } return ret; } diff --git a/net/netfilter/ipset/ip_set_hash_ipportip.c b/net/netfilter/ipset/ip_set_hash_ipportip.c index 39a01934b153..b9ac2efaa15c 100644 --- a/net/netfilter/ipset/ip_set_hash_ipportip.c +++ b/net/netfilter/ipset/ip_set_hash_ipportip.c @@ -182,7 +182,7 @@ hash_ipportip4_uadt(struct ip_set *set, struct nlattr *tb[], if (retried) ip = ntohl(h->next.ip); - for (; ip <= ip_to; ip++) { + for (; ip <= ip_to;) { p = retried && ip == ntohl(h->next.ip) ? ntohs(h->next.port) : port; for (; p <= port_to; p++, i++) { @@ -199,6 +199,9 @@ hash_ipportip4_uadt(struct ip_set *set, struct nlattr *tb[], ret = 0; } + if (ip == ip_to) + break; + ip++; } return ret; } diff --git a/net/netfilter/ipset/ip_set_hash_ipportnet.c b/net/netfilter/ipset/ip_set_hash_ipportnet.c index 5c6de605a9fb..2d6652d43199 100644 --- a/net/netfilter/ipset/ip_set_hash_ipportnet.c +++ b/net/netfilter/ipset/ip_set_hash_ipportnet.c @@ -274,7 +274,7 @@ hash_ipportnet4_uadt(struct ip_set *set, struct nlattr *tb[], p = port; ip2 = ip2_from; } - for (; ip <= ip_to; ip++) { + for (; ip <= ip_to;) { e.ip = htonl(ip); for (; p <= port_to; p++) { e.port = htons(p); @@ -298,6 +298,9 @@ hash_ipportnet4_uadt(struct ip_set *set, struct nlattr *tb[], ip2 = ip2_from; } p = port; + if (ip == ip_to) + break; + ip++; } return ret; } -- cgit v1.2.3 From a6cb3ff979855f7f0ee9450a947fe8f96c2ba37a Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 12 May 2026 11:30:49 +0200 Subject: netfilter: nft_inner: release local_lock before re-enabling softirqs Quoting sashiko: In the error path, local_bh_enable() is called before local_unlock_nested_bh(). Fixes: ba36fada9ab4 ("netfilter: nft_inner: Use nested-BH locking for nft_pcpu_tun_ctx") Signed-off-by: Florian Westphal Reviewed-by: Fernando Fernandez Mancera Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_inner.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/netfilter/nft_inner.c b/net/netfilter/nft_inner.c index 859aa38e333b..d14ca157910b 100644 --- a/net/netfilter/nft_inner.c +++ b/net/netfilter/nft_inner.c @@ -246,8 +246,8 @@ static bool nft_inner_restore_tun_ctx(const struct nft_pktinfo *pkt, local_lock_nested_bh(&nft_pcpu_tun_ctx.bh_lock); this_cpu_tun_ctx = this_cpu_ptr(&nft_pcpu_tun_ctx.ctx); if (this_cpu_tun_ctx->cookie != (unsigned long)pkt->skb) { - local_bh_enable(); local_unlock_nested_bh(&nft_pcpu_tun_ctx.bh_lock); + local_bh_enable(); return false; } *tun_ctx = *this_cpu_tun_ctx; -- cgit v1.2.3 From 4322dcde6b4173c2d8e8e6118ed290794263bcc8 Mon Sep 17 00:00:00 2001 From: Zhengchuan Liang Date: Wed, 13 May 2026 15:57:17 +0800 Subject: netfilter: ip6t_hbh: reject oversized option lists struct ip6t_opts stores at most IP6T_OPTS_OPTSNR option descriptors, but hbh_mt6_check() does not reject larger optsnr values supplied from userspace. Validate optsnr in the rule setup path so only match data that fits the fixed-size opts array can be installed. This follows the existing xtables pattern of rejecting invalid user-provided counts in checkentry() and keeps the packet matching path unchanged. `struct ip6t_opts` has a fixed `opts[IP6T_OPTS_OPTSNR]` array, where `IP6T_OPTS_OPTSNR` is 16, then off-by-one array access is possible: [ 137.924693][ T8692] UBSAN: array-index-out-of-bounds in ../net/ipv6/netfilter/ip6t_hbh.c:110:29 [ 137.926167][ T8692] index 16 is out of range for type '__u16 [16]' Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Zhengchuan Liang Signed-off-by: Ren Wei Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/ip6t_hbh.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net') diff --git a/net/ipv6/netfilter/ip6t_hbh.c b/net/ipv6/netfilter/ip6t_hbh.c index e7a3fb9355ee..450dd53846a2 100644 --- a/net/ipv6/netfilter/ip6t_hbh.c +++ b/net/ipv6/netfilter/ip6t_hbh.c @@ -168,6 +168,10 @@ static int hbh_mt6_check(const struct xt_mtchk_param *par) pr_debug("unknown flags %X\n", optsinfo->invflags); return -EINVAL; } + if (optsinfo->optsnr > IP6T_OPTS_OPTSNR) { + pr_debug("too many supported opts specified\n"); + return -EINVAL; + } if (optsinfo->flags & IP6T_OPTS_NSTRICT) { pr_debug("Not strict - not implemented"); -- cgit v1.2.3 From c0c42a0fb27144c1cd7509f94bec0d3bcca98c72 Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Thu, 14 May 2026 10:55:11 +0200 Subject: netfilter: ipset: Fix data race between add and list header in all hash types The "ipset list -terse" command is actually a dump operation which may run parallel with "ipset add" commands, which can trigger an internal resizing of the hash type of sets just being dumped. However, dumping just the header part of the set was not protected against underlying resizing. Fix it by protecting the header dumping part as well. Fixes: c4c997839cf9 ("netfilter: ipset: Fix parallel resizing and listing of the same set") Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c index 0874029cb0f2..3706b4a85a0f 100644 --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -1649,13 +1649,13 @@ dump_last: if (cb->args[IPSET_CB_PROTO] > IPSET_PROTOCOL_MIN && nla_put_net16(skb, IPSET_ATTR_INDEX, htons(index))) goto nla_put_failure; + if (set->variant->uref) + set->variant->uref(set, cb, true); ret = set->variant->head(set, skb); if (ret < 0) goto release_refcount; if (dump_flags & IPSET_FLAG_LIST_HEADER) goto next_set; - if (set->variant->uref) - set->variant->uref(set, cb, true); fallthrough; default: ret = set->variant->list(set, skb, cb); -- cgit v1.2.3 From 2358f7427ccd6ec8867a48205d8fcec973683a3f Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Fri, 8 May 2026 22:58:58 +0200 Subject: netfilter: ipset: Fix data race between add and dump in all hash types When adding a new entry to the next position in the existing hash bucket, the position index was incremented too early and parallel dump could read it before the entry was populated with the value. Move the setting of the position index after populating the entry. v2: Position counting fixed, noticed by Florian Westphal. Fixes: 18f84d41d34f ("netfilter: ipset: Introduce RCU locking in hash:* types") Reported-by: syzbot+786c889f046e8b003ca6@syzkaller.appspotmail.com Reported-by: syzbot+1da17e4b41d795df059e@syzkaller.appspotmail.com Reported-by: syzbot+421c5f3ff8e9493084d9@syzkaller.appspotmail.com Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_hash_gen.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h index b79e5dd2af03..133ce4611eed 100644 --- a/net/netfilter/ipset/ip_set_hash_gen.h +++ b/net/netfilter/ipset/ip_set_hash_gen.h @@ -844,7 +844,7 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext, const struct mtype_elem *d = value; struct mtype_elem *data; struct hbucket *n, *old = ERR_PTR(-ENOENT); - int i, j = -1, ret; + int i, j = -1, npos = 0, ret; bool flag_exist = flags & IPSET_FLAG_EXIST; bool deleted = false, forceadd = false, reuse = false; u32 r, key, multi = 0, elements, maxelem; @@ -889,6 +889,7 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext, ext_size(AHASH_INIT_SIZE, set->dsize); goto copy_elem; } + npos = n->pos; for (i = 0; i < n->pos; i++) { if (!test_bit(i, n->used)) { /* Reuse first deleted entry */ @@ -962,7 +963,8 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext, } copy_elem: - j = n->pos++; + j = npos; + npos = n->pos + 1; data = ahash_data(n, j, set->dsize); copy_data: t->hregion[r].elements++; @@ -985,6 +987,7 @@ overwrite_extensions: if (SET_WITH_TIMEOUT(set)) ip_set_timeout_set(ext_timeout(data, set), ext->timeout); smp_mb__before_atomic(); + n->pos = npos; set_bit(j, n->used); if (old != ERR_PTR(-ENOENT)) { rcu_assign_pointer(hbucket(t, key), n); -- cgit v1.2.3 From 7f7445840b7771338618930e45ee641104b38ed8 Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Thu, 14 May 2026 10:55:13 +0200 Subject: netfilter: ipset: annotate "pos" for concurrent readers/writers The "pos" structure member of struct hbucket stores the first free slot in the hash bucket of a hash type of set and there are concurrent readers/writers. Annotate accesses properly. Fixes: 18f84d41d34f ("netfilter: ipset: Introduce RCU locking in hash:* types") Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_hash_gen.h | 62 +++++++++++++++++++++-------------- 1 file changed, 38 insertions(+), 24 deletions(-) (limited to 'net') diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h index 133ce4611eed..04e4627ddfc1 100644 --- a/net/netfilter/ipset/ip_set_hash_gen.h +++ b/net/netfilter/ipset/ip_set_hash_gen.h @@ -386,8 +386,9 @@ static void mtype_ext_cleanup(struct ip_set *set, struct hbucket *n) { int i; + u8 pos = smp_load_acquire(&n->pos); - for (i = 0; i < n->pos; i++) + for (i = 0; i < pos; i++) if (test_bit(i, n->used)) ip_set_ext_destroy(set, ahash_data(n, i, set->dsize)); } @@ -490,7 +491,7 @@ mtype_gc_do(struct ip_set *set, struct htype *h, struct htable *t, u32 r) #ifdef IP_SET_HASH_WITH_NETS u8 k; #endif - u8 htable_bits = t->htable_bits; + u8 pos, htable_bits = t->htable_bits; spin_lock_bh(&t->hregion[r].lock); for (i = ahash_bucket_start(r, htable_bits); @@ -498,7 +499,8 @@ mtype_gc_do(struct ip_set *set, struct htype *h, struct htable *t, u32 r) n = __ipset_dereference(hbucket(t, i)); if (!n) continue; - for (j = 0, d = 0; j < n->pos; j++) { + pos = smp_load_acquire(&n->pos); + for (j = 0, d = 0; j < pos; j++) { if (!test_bit(j, n->used)) { d++; continue; @@ -534,7 +536,7 @@ mtype_gc_do(struct ip_set *set, struct htype *h, struct htable *t, u32 r) /* Still try to delete expired elements. */ continue; tmp->size = n->size - AHASH_INIT_SIZE; - for (j = 0, d = 0; j < n->pos; j++) { + for (j = 0, d = 0; j < pos; j++) { if (!test_bit(j, n->used)) continue; data = ahash_data(n, j, dsize); @@ -623,7 +625,7 @@ mtype_resize(struct ip_set *set, bool retried) { struct htype *h = set->data; struct htable *t, *orig; - u8 htable_bits; + u8 pos, htable_bits; size_t hsize, dsize = set->dsize; #ifdef IP_SET_HASH_WITH_NETS u8 flags; @@ -685,7 +687,8 @@ retry: n = __ipset_dereference(hbucket(orig, i)); if (!n) continue; - for (j = 0; j < n->pos; j++) { + pos = smp_load_acquire(&n->pos); + for (j = 0; j < pos; j++) { if (!test_bit(j, n->used)) continue; data = ahash_data(n, j, dsize); @@ -809,9 +812,10 @@ mtype_ext_size(struct ip_set *set, u32 *elements, size_t *ext_size) { struct htype *h = set->data; const struct htable *t; - u32 i, j, r; struct hbucket *n; struct mtype_elem *data; + u32 i, j, r; + u8 pos; t = rcu_dereference_bh(h->table); for (r = 0; r < ahash_numof_locks(t->htable_bits); r++) { @@ -820,7 +824,8 @@ mtype_ext_size(struct ip_set *set, u32 *elements, size_t *ext_size) n = rcu_dereference_bh(hbucket(t, i)); if (!n) continue; - for (j = 0; j < n->pos; j++) { + pos = smp_load_acquire(&n->pos); + for (j = 0; j < pos; j++) { if (!test_bit(j, n->used)) continue; data = ahash_data(n, j, set->dsize); @@ -844,10 +849,11 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext, const struct mtype_elem *d = value; struct mtype_elem *data; struct hbucket *n, *old = ERR_PTR(-ENOENT); - int i, j = -1, npos = 0, ret; + int i, j = -1, ret; bool flag_exist = flags & IPSET_FLAG_EXIST; bool deleted = false, forceadd = false, reuse = false; u32 r, key, multi = 0, elements, maxelem; + u8 npos = 0; rcu_read_lock_bh(); t = rcu_dereference_bh(h->table); @@ -889,8 +895,8 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext, ext_size(AHASH_INIT_SIZE, set->dsize); goto copy_elem; } - npos = n->pos; - for (i = 0; i < n->pos; i++) { + npos = smp_load_acquire(&n->pos); + for (i = 0; i < npos; i++) { if (!test_bit(i, n->used)) { /* Reuse first deleted entry */ if (j == -1) { @@ -934,7 +940,7 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext, if (elements >= maxelem) goto set_full; /* Create a new slot */ - if (n->pos >= n->size) { + if (npos >= n->size) { #ifdef IP_SET_HASH_WITH_MULTI if (h->bucketsize >= AHASH_MAX_TUNED) goto set_full; @@ -963,8 +969,7 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext, } copy_elem: - j = npos; - npos = n->pos + 1; + j = npos++; data = ahash_data(n, j, set->dsize); copy_data: t->hregion[r].elements++; @@ -987,7 +992,8 @@ overwrite_extensions: if (SET_WITH_TIMEOUT(set)) ip_set_timeout_set(ext_timeout(data, set), ext->timeout); smp_mb__before_atomic(); - n->pos = npos; + /* Ensure all data writes are visible before updating position */ + smp_store_release(&n->pos, npos); set_bit(j, n->used); if (old != ERR_PTR(-ENOENT)) { rcu_assign_pointer(hbucket(t, key), n); @@ -1046,6 +1052,7 @@ mtype_del(struct ip_set *set, void *value, const struct ip_set_ext *ext, int i, j, k, r, ret = -IPSET_ERR_EXIST; u32 key, multi = 0; size_t dsize = set->dsize; + u8 pos; /* Userspace add and resize is excluded by the mutex. * Kernespace add does not trigger resize. @@ -1061,7 +1068,8 @@ mtype_del(struct ip_set *set, void *value, const struct ip_set_ext *ext, n = rcu_dereference_bh(hbucket(t, key)); if (!n) goto out; - for (i = 0, k = 0; i < n->pos; i++) { + pos = smp_load_acquire(&n->pos); + for (i = 0, k = 0; i < pos; i++) { if (!test_bit(i, n->used)) { k++; continue; @@ -1075,8 +1083,8 @@ mtype_del(struct ip_set *set, void *value, const struct ip_set_ext *ext, ret = 0; clear_bit(i, n->used); smp_mb__after_atomic(); - if (i + 1 == n->pos) - n->pos--; + if (i + 1 == pos) + smp_store_release(&n->pos, --pos); t->hregion[r].elements--; #ifdef IP_SET_HASH_WITH_NETS for (j = 0; j < IPSET_NET_COUNT; j++) @@ -1097,11 +1105,11 @@ mtype_del(struct ip_set *set, void *value, const struct ip_set_ext *ext, x->flags = flags; } } - for (; i < n->pos; i++) { + for (; i < pos; i++) { if (!test_bit(i, n->used)) k++; } - if (k == n->pos) { + if (k == pos) { t->hregion[r].ext_size -= ext_size(n->size, dsize); rcu_assign_pointer(hbucket(t, key), NULL); kfree_rcu(n, rcu); @@ -1112,7 +1120,7 @@ mtype_del(struct ip_set *set, void *value, const struct ip_set_ext *ext, if (!tmp) goto out; tmp->size = n->size - AHASH_INIT_SIZE; - for (j = 0, k = 0; j < n->pos; j++) { + for (j = 0, k = 0; j < pos; j++) { if (!test_bit(j, n->used)) continue; data = ahash_data(n, j, dsize); @@ -1173,6 +1181,7 @@ mtype_test_cidrs(struct ip_set *set, struct mtype_elem *d, int ret, i, j = 0; #endif u32 key, multi = 0; + u8 pos; pr_debug("test by nets\n"); for (; j < NLEN && h->nets[j].cidr[0] && !multi; j++) { @@ -1190,7 +1199,8 @@ mtype_test_cidrs(struct ip_set *set, struct mtype_elem *d, n = rcu_dereference_bh(hbucket(t, key)); if (!n) continue; - for (i = 0; i < n->pos; i++) { + pos = smp_load_acquire(&n->pos); + for (i = 0; i < pos; i++) { if (!test_bit(i, n->used)) continue; data = ahash_data(n, i, set->dsize); @@ -1224,6 +1234,7 @@ mtype_test(struct ip_set *set, void *value, const struct ip_set_ext *ext, struct mtype_elem *data; int i, ret = 0; u32 key, multi = 0; + u8 pos; rcu_read_lock_bh(); t = rcu_dereference_bh(h->table); @@ -1246,7 +1257,8 @@ mtype_test(struct ip_set *set, void *value, const struct ip_set_ext *ext, ret = 0; goto out; } - for (i = 0; i < n->pos; i++) { + pos = smp_load_acquire(&n->pos); + for (i = 0; i < pos; i++) { if (!test_bit(i, n->used)) continue; data = ahash_data(n, i, set->dsize); @@ -1363,6 +1375,7 @@ mtype_list(const struct ip_set *set, /* We assume that one hash bucket fills into one page */ void *incomplete; int i, ret = 0; + u8 pos; atd = nla_nest_start(skb, IPSET_ATTR_ADT); if (!atd) @@ -1381,7 +1394,8 @@ mtype_list(const struct ip_set *set, cb->args[IPSET_CB_ARG0], t, n); if (!n) continue; - for (i = 0; i < n->pos; i++) { + pos = smp_load_acquire(&n->pos); + for (i = 0; i < pos; i++) { if (!test_bit(i, n->used)) continue; e = ahash_data(n, i, set->dsize); -- cgit v1.2.3 From b2870fc21601db9133bc70c48c603b487614fa3b Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Thu, 14 May 2026 16:46:38 +0200 Subject: netfilter: br_netfilter: Reallocate headroom if necessary in neigh_hh_bridge() neigh_hh_bridge() assumes the skb always has sufficient headroom to copy the aligned L2 header. This assumption can trigger the crash reported below using the following netfilter setup: $modprobe br_netfilter $sysctl -w net.bridge.bridge-nf-call-iptables=1 $root@OpenWrt:~# nft list ruleset table ip nat { chain prerouting { type nat hook prerouting priority dstnat; policy accept; ip daddr 192.168.83.123 dnat to 192.168.83.120 } } - iperf3 client (192.168.83.119) --> bridge (192.168.83.118) --> iperf3 server (192.168.83.120) the iperf3 client is sending packet for 192.168.83.123 to the bridge device. [ 1579.036575] Unable to handle kernel write to read-only memory at virtual address ffffff8004d76ffe [ 1579.045482] Mem abort info: [ 1579.048273] ESR = 0x000000009600004f [ 1579.052024] EC = 0x25: DABT (current EL), IL = 32 bits [ 1579.057363] SET = 0, FnV = 0 [ 1579.060417] EA = 0, S1PTW = 0 [ 1579.063550] FSC = 0x0f: level 3 permission fault [ 1579.068345] Data abort info: [ 1579.071224] ISV = 0, ISS = 0x0000004f, ISS2 = 0x00000000 [ 1579.076720] CM = 0, WnR = 1, TnD = 0, TagAccess = 0 [ 1579.081770] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 1579.087092] swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000080dc4000 [ 1579.093794] [ffffff8004d76ffe] pgd=180000009ffff003, p4d=180000009ffff003, pud=180000009ffff003, pmd=180000009ffe3003, pte=0060000084d76787 [ 1579.106343] Internal error: Oops: 000000009600004f [#1] SMP [ 1579.193824] CPU: 0 UID: 0 PID: 235 Comm: napi/qdma_eth-3 Tainted: G O 6.12.57 #0 [ 1579.202614] Tainted: [O]=OOT_MODULE [ 1579.206102] Hardware name: Airoha AN7581 Evaluation Board (DT) [ 1579.211929] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 1579.218889] pc : br_nf_pre_routing_finish_bridge+0x1ac/0xcc8 [br_netfilter] [ 1579.225859] lr : br_nf_pre_routing_finish_bridge+0x18c/0xcc8 [br_netfilter] [ 1579.232822] sp : ffffffc0817cba20 [ 1579.236128] x29: ffffffc0817cba20 x28: 0000000000000000 x27: ffffff8002b89000 [ 1579.243273] x26: ffffff8004d7700e x25: 0000000000000008 x24: 0000000000000000 [ 1579.250416] x23: ffffffc08179d4c0 x22: 0000000000000000 x21: ffffffc08179d4c0 [ 1579.257561] x20: ffffff8004d9b800 x19: ffffff8015010000 x18: 0000000000000014 [ 1579.264704] x17: ffffffbf9e930000 x16: ffffffc0817c8000 x15: 0000000000000070 [ 1579.271848] x14: 0000000000000080 x13: 0000000000000001 x12: 0000000000000000 [ 1579.278993] x11: ffffffc0798caae0 x10: ffffff8014db6fd8 x9 : 0000000000000000 [ 1579.286136] x8 : 0000000000000003 x7 : ffffffc08171f628 x6 : 000000001a3b83d3 [ 1579.293281] x5 : 0000000000000000 x4 : 1beb76f22fee0000 x3 : ffffff8004d7700e [ 1579.300425] x2 : 0000000000000000 x1 : ffffff8004d9b8bc x0 : ffffff80026ed000 [ 1579.307570] Call trace: [ 1579.310018] br_nf_pre_routing_finish_bridge+0x1ac/0xcc8 [br_netfilter] [ 1579.316632] br_nf_hook_thresh+0xd4/0x14bc [br_netfilter] [ 1579.322032] br_nf_hook_thresh+0x250/0x14bc [br_netfilter] [ 1579.327517] br_nf_hook_thresh+0x76c/0x14bc [br_netfilter] [ 1579.333003] br_handle_frame+0x180/0x480 [ 1579.336935] __netif_receive_skb_core.constprop.0+0x540/0xf40 [ 1579.342682] __netif_receive_skb_one_core+0x28/0x50 [ 1579.347561] process_backlog+0x98/0x1e0 [ 1579.351398] __napi_poll+0x34/0x1c4 [ 1579.354887] net_rx_action+0x178/0x330 [ 1579.358638] handle_softirqs+0x108/0x2d4 [ 1579.362560] __do_softirq+0x10/0x18 [ 1579.366051] ____do_softirq+0xc/0x20 [ 1579.369627] call_on_irq_stack+0x30/0x4c [ 1579.373550] do_softirq_own_stack+0x18/0x20 [ 1579.377734] do_softirq+0x4c/0x60 [ 1579.381050] __local_bh_enable_ip+0x88/0x98 [ 1579.385234] napi_threaded_poll_loop+0x188/0x21c [ 1579.389853] napi_threaded_poll+0x70/0x80 [ 1579.393863] kthread+0xd8/0xdc [ 1579.396918] ret_from_fork+0x10/0x20 [ 1579.400499] Code: 88dffc22 3707ffc2 f9406663 f9406684 (f81f0064) [ 1579.406589] ---[ end trace 0000000000000000 ]--- [ 1579.411209] Kernel panic - not syncing: Oops: Fatal exception in interrupt [ 1579.418083] SMP: stopping secondary CPUs [ 1579.422012] Kernel Offset: disabled Fix the issue reallocating the skb headroom if necessary in neigh_hh_bridge routine. Fixes: e179e6322ac33 ("netfilter: bridge-netfilter: Fix MAC header handling with IP DNAT") Reviewed-by: Ido Schimmel Signed-off-by: Lorenzo Bianconi Signed-off-by: Pablo Neira Ayuso --- net/bridge/br_netfilter_hooks.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index 0ab1c94db4b9..0a394e5f4391 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -297,7 +297,11 @@ int br_nf_pre_routing_finish_bridge(struct net *net, struct sock *sk, struct sk_ goto free_skb; } - neigh_hh_bridge(&neigh->hh, skb); + if (neigh_hh_bridge(&neigh->hh, skb)) { + neigh_release(neigh); + goto free_skb; + } + skb->dev = br_indev; ret = br_handle_frame_finish(net, sk, skb); -- cgit v1.2.3 From e196115ec330a18de415bdb9f5071aa9f08e53ce Mon Sep 17 00:00:00 2001 From: Haoze Xie Date: Fri, 15 May 2026 11:19:02 +0800 Subject: netfilter: nf_queue: hold bridge skb->dev while queued br_pass_frame_up() rewrites skb->dev from the ingress port to the bridge master before queueing bridge LOCAL_IN packets. NFQUEUE only holds references on state.in/out and bridge physdevs, so a queued bridge packet can retain a freed bridge master in skb->dev until reinjection. When the verdict is reinjected later, br_netif_receive_skb() re-enters the receive path with skb->dev still pointing at the freed bridge master, triggering a use-after-free. Store skb->dev in the queue entry, hold a reference on it for the queue lifetime, and use the saved device when dropping queued packets during NETDEV_DOWN handling. Fixes: ac2863445686 ("netfilter: bridge: add nf_afinfo to enable queuing to userspace") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Haoze Xie Signed-off-by: Ren Wei Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_queue.c | 4 +++- net/netfilter/nfnetlink_queue.c | 2 ++ 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c index a6c81c04b3a5..57b450024a99 100644 --- a/net/netfilter/nf_queue.c +++ b/net/netfilter/nf_queue.c @@ -61,6 +61,7 @@ static void nf_queue_entry_release_refs(struct nf_queue_entry *entry) struct nf_hook_state *state = &entry->state; /* Release those devices we held, or Alexey will kill me. */ + dev_put(entry->skb_dev); dev_put(state->in); dev_put(state->out); if (state->sk) @@ -102,6 +103,7 @@ bool nf_queue_entry_get_refs(struct nf_queue_entry *entry) if (state->sk && !refcount_inc_not_zero(&state->sk->sk_refcnt)) return false; + dev_hold(entry->skb_dev); dev_hold(state->in); dev_hold(state->out); @@ -202,11 +204,11 @@ static int __nf_queue(struct sk_buff *skb, const struct nf_hook_state *state, *entry = (struct nf_queue_entry) { .skb = skb, + .skb_dev = skb->dev, .state = *state, .hook_index = index, .size = sizeof(*entry) + route_key_size, }; - __nf_queue_entry_init_physdevs(entry); if (!nf_queue_entry_get_refs(entry)) { diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 58304fd1f70f..984a0eb9e149 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -1212,6 +1212,8 @@ dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex) if (physinif == ifindex || physoutif == ifindex) return 1; #endif + if (entry->skb_dev && entry->skb_dev->ifindex == ifindex) + return 1; if (entry->state.in) if (entry->state.in->ifindex == ifindex) return 1; -- cgit v1.2.3 From 0039ac8305064e455f04d412ec3896c4fe41d04f Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 16 May 2026 22:10:08 +0200 Subject: batman-adv: fix batadv_skb_is_frag() kernel-doc The kernel-doc comment for batadv_skb_is_frag() contained two errors: * the function description referred to "gain a unicast packet" instead of "contains unicast fragment". * the Return section omitted "merged" from "newly skb", leaving the description grammatically incorrect and inconsistent with the function description. Fixes: bc62216dc8e2 ("batman-adv: frag: disallow unicast fragment in fragment") Signed-off-by: Sven Eckelmann --- net/batman-adv/fragmentation.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 4a594aa2ebf6..e9553db42349 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -305,10 +305,10 @@ free: } /** - * batadv_skb_is_frag() - check if newly merged skb is gain a unicast packet + * batadv_skb_is_frag() - check if newly merged skb contains unicast fragment * @skb: newly merged skb * - * Return: if newly skb is of type BATADV_UNICAST_FRAG + * Return: if newly merged skb is of type BATADV_UNICAST_FRAG */ static bool batadv_skb_is_frag(struct sk_buff *skb) { -- cgit v1.2.3 From 9e7f36ab5b7bf68463faa5f7b926fea8f35597bb Mon Sep 17 00:00:00 2001 From: Weiming Shi Date: Thu, 14 May 2026 05:38:08 -0700 Subject: net: appletalk: fix NULL pointer dereference in aarp_send_ddp() aarp_send_ddp() calls atalk_find_dev_addr(dev) in the LocalTalk fast path without checking for NULL. When the device has no AppleTalk interface configured (dev->atalk_ptr == NULL), this leads to a NULL pointer dereference at the at->s_net access. KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:aarp_send_ddp (net/appletalk/aarp.c:552 (discriminator 2)) Call Trace: atalk_sendmsg (net/appletalk/ddp.c:1715) __sys_sendto (net/socket.c:2265 (discriminator 1)) __x64_sys_sendto (net/socket.c:2272) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Add a NULL check consistent with the other callers of atalk_find_dev_addr(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Xiang Mei Signed-off-by: Weiming Shi Link: https://patch.msgid.link/20260514123806.3085961-3-bestswngs@gmail.com Signed-off-by: Jakub Kicinski --- net/appletalk/aarp.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'net') diff --git a/net/appletalk/aarp.c b/net/appletalk/aarp.c index e7315c01a299..30493ea3c010 100644 --- a/net/appletalk/aarp.c +++ b/net/appletalk/aarp.c @@ -542,6 +542,11 @@ int aarp_send_ddp(struct net_device *dev, struct sk_buff *skb, struct ddpehdr *ddp = (struct ddpehdr *)skb->data; int ft = 2; + if (!at) { + kfree_skb(skb); + return NET_XMIT_DROP; + } + /* * Compressible ? * -- cgit v1.2.3 From bae3ee802c21e83ad1eb805519e6f32ea528b4d2 Mon Sep 17 00:00:00 2001 From: Ilya Maximets Date: Thu, 14 May 2026 20:46:31 +0200 Subject: openvswitch: vport: fix race between linking and the device notifier Sashiko reports that it is technically possible that we got the device reference, but by the time we're linking it to the OVS datapath, it may be already in the process of being deleted. In this case if the notifier wins the race for RTNL, it will see that the device is not yet in the OVS datapath (ovs_netdev_get_vport() will fail in the dp_device_event()) and will do nothing. Then the ovs_netdev_link() will take the RTNL and link the unregistering device to OVS datapath. Eventually, netdev_wait_allrefs_any() will re-broadcast the event and the device will be properly detached, but it will take at least a second before that happens, so it's not something we should rely on. Let's avoid linking the non-registered device in the first place. Note: As per documentation, RTNL doesn't protect the reg_state, but it actually does for all the state transitions we care about here, so it should not be necessary to use READ_ONCE or taking the instance lock. We can still do that, but we have a few more places even in this file where the reg_state is accessed without those while under RTNL, and many more places like this across the kernel code, so it might make more sense to change all of them in a more centralized fashion in the future, if necessary. Fixes: ccb1352e76cf ("net: Add Open vSwitch kernel components.") Signed-off-by: Ilya Maximets Reviewed-by: Aaron Conole Acked-by: Eelco Chaudron Link: https://patch.msgid.link/20260514184702.2461435-1-i.maximets@ovn.org Signed-off-by: Jakub Kicinski --- net/openvswitch/vport-netdev.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'net') diff --git a/net/openvswitch/vport-netdev.c b/net/openvswitch/vport-netdev.c index c42642075685..e7e8490a53d8 100644 --- a/net/openvswitch/vport-netdev.c +++ b/net/openvswitch/vport-netdev.c @@ -83,6 +83,14 @@ struct vport *ovs_netdev_link(struct vport *vport, bool tunnel) } rtnl_lock(); + /* Do not link devices that are not registered to avoid a potential + * race with the NETDEV_UNREGISTER notification in dp_device_event(). + */ + if (vport->dev->reg_state != NETREG_REGISTERED) { + err = -ENODEV; + goto error_put_unlock; + } + err = netdev_master_upper_dev_link(vport->dev, get_dpdev(vport->dp), NULL, NULL, NULL); -- cgit v1.2.3 From f8ce8b8331a1bc44ad4905886a482214d428b253 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 9 May 2026 22:44:12 +0200 Subject: batman-adv: v: stop OGMv2 on disabled interface When a batadv_hard_iface is disabled, its mesh_iface pointer is set to NULL. However, batadv_v_ogm_send_meshif() may still dispatch OGMs via batadv_v_ogm_queue_on_if() for interfaces that have since lost their mesh_iface association. This results in a NULL pointer dereference when batadv_v_ogm_queue_on_if() unconditionally calls netdev_priv() on the now NULL hard_iface->mesh_iface to retrieve the batadv_priv. It is necessary to ensure that the batadv_v_ogm_queue_on_if() checks that it is using the same mesh_iface for which batadv_v_ogm_send_meshif() was called. Cc: stable@kernel.org Fixes: 0da0035942d4 ("batman-adv: OGMv2 - add basic infrastructure") Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Reviewed-by: Yuan Tan Signed-off-by: Sven Eckelmann --- net/batman-adv/bat_v_ogm.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) (limited to 'net') diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index e3870492dab7..e955b4940c72 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -113,14 +113,14 @@ static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv) /** * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface + * @bat_priv: the bat priv with all the mesh interface information * @skb: the OGM to send * @hard_iface: the interface to use to send the OGM */ -static void batadv_v_ogm_send_to_if(struct sk_buff *skb, +static void batadv_v_ogm_send_to_if(struct batadv_priv *bat_priv, + struct sk_buff *skb, struct batadv_hard_iface *hard_iface) { - struct batadv_priv *bat_priv = netdev_priv(hard_iface->mesh_iface); - if (hard_iface->if_status != BATADV_IF_ACTIVE) { kfree_skb(skb); return; @@ -187,6 +187,7 @@ static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface) /** * batadv_v_ogm_aggr_send() - flush & send aggregation queue + * @bat_priv: the bat priv with all the mesh interface information * @hard_iface: the interface with the aggregation queue to flush * * Aggregates all OGMv2 packets currently in the aggregation queue into a @@ -196,7 +197,8 @@ static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface) * * Caller needs to hold the hard_iface->bat_v.aggr_list.lock. */ -static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface) +static void batadv_v_ogm_aggr_send(struct batadv_priv *bat_priv, + struct batadv_hard_iface *hard_iface) { unsigned int aggr_len = hard_iface->bat_v.aggr_len; struct sk_buff *skb_aggr; @@ -226,27 +228,32 @@ static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface) consume_skb(skb); } - batadv_v_ogm_send_to_if(skb_aggr, hard_iface); + batadv_v_ogm_send_to_if(bat_priv, skb_aggr, hard_iface); } /** * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface + * @bat_priv: the bat priv with all the mesh interface information * @skb: the OGM to queue * @hard_iface: the interface to queue the OGM on */ -static void batadv_v_ogm_queue_on_if(struct sk_buff *skb, +static void batadv_v_ogm_queue_on_if(struct batadv_priv *bat_priv, + struct sk_buff *skb, struct batadv_hard_iface *hard_iface) { - struct batadv_priv *bat_priv = netdev_priv(hard_iface->mesh_iface); + if (hard_iface->mesh_iface != bat_priv->mesh_iface) { + kfree_skb(skb); + return; + } if (!atomic_read(&bat_priv->aggregated_ogms)) { - batadv_v_ogm_send_to_if(skb, hard_iface); + batadv_v_ogm_send_to_if(bat_priv, skb, hard_iface); return; } spin_lock_bh(&hard_iface->bat_v.aggr_list.lock); if (!batadv_v_ogm_queue_left(skb, hard_iface)) - batadv_v_ogm_aggr_send(hard_iface); + batadv_v_ogm_aggr_send(bat_priv, hard_iface); hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb); __skb_queue_tail(&hard_iface->bat_v.aggr_list, skb); @@ -343,7 +350,7 @@ static void batadv_v_ogm_send_meshif(struct batadv_priv *bat_priv) break; } - batadv_v_ogm_queue_on_if(skb_tmp, hard_iface); + batadv_v_ogm_queue_on_if(bat_priv, skb_tmp, hard_iface); batadv_hardif_put(hard_iface); } rcu_read_unlock(); @@ -383,12 +390,14 @@ void batadv_v_ogm_aggr_work(struct work_struct *work) { struct batadv_hard_iface_bat_v *batv; struct batadv_hard_iface *hard_iface; + struct batadv_priv *bat_priv; batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work); hard_iface = container_of(batv, struct batadv_hard_iface, bat_v); + bat_priv = netdev_priv(hard_iface->mesh_iface); spin_lock_bh(&hard_iface->bat_v.aggr_list.lock); - batadv_v_ogm_aggr_send(hard_iface); + batadv_v_ogm_aggr_send(bat_priv, hard_iface); spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock); batadv_v_ogm_start_queue_timer(hard_iface); @@ -578,7 +587,7 @@ static void batadv_v_ogm_forward(struct batadv_priv *bat_priv, if_outgoing->net_dev->name, ntohl(ogm_forward->throughput), ogm_forward->ttl, if_incoming->net_dev->name); - batadv_v_ogm_queue_on_if(skb, if_outgoing); + batadv_v_ogm_queue_on_if(bat_priv, skb, if_outgoing); out: batadv_orig_ifinfo_put(orig_ifinfo); -- cgit v1.2.3 From 501368506563e151b322c8c3f228b796e615b90d Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Thu, 14 May 2026 16:33:12 +0200 Subject: batman-adv: tvlv: abort OGM send on tvlv append failure batadv_tvlv_container_ogm_append() could fail in two ways: a memory allocation failure when resizing the packet buffer, or the tvlv data exceeding U16_MAX bytes. In both cases the function previously returned the old (now stale) tvlv_value_len rather than signalling an error, causing the OGM/OGM2 send path to transmit a packet whose TVLV length field no longer matched the actual buffer contents. And because it also didn't fill in the new TVLV data, sending either uninitialized or corrupted data on the wire. All errors in batadv_tvlv_container_ogm_append() must be forwarded to the caller. And the caller must abort the send of the OGM2. For B.A.T.M.A.N. IV, it is currently not allowed to abort the send. The non-TVLV part of the OGM must be queued up instead. Cc: stable@kernel.org Fixes: ef26157747d4 ("batman-adv: tvlv - basic infrastructure") Signed-off-by: Sven Eckelmann --- net/batman-adv/bat_iv_ogm.c | 16 +++++++++++++--- net/batman-adv/bat_v_ogm.c | 26 ++++++++++++++------------ net/batman-adv/tvlv.c | 17 ++++++++++++----- net/batman-adv/tvlv.h | 2 +- 4 files changed, 40 insertions(+), 21 deletions(-) (limited to 'net') diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 74ef7dc2b2f9..7ad26128b5f7 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -790,6 +790,7 @@ static void batadv_iv_ogm_schedule_buff(struct batadv_hard_iface *hard_iface) u32 seqno; u16 tvlv_len = 0; unsigned long send_time; + int ret; lockdep_assert_held(&hard_iface->bat_iv.ogm_buff_mutex); @@ -813,9 +814,18 @@ static void batadv_iv_ogm_schedule_buff(struct batadv_hard_iface *hard_iface) * appended as it may alter the tt tvlv container */ batadv_tt_local_commit_changes(bat_priv); - tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, ogm_buff, - ogm_buff_len, - BATADV_OGM_HLEN); + ret = batadv_tvlv_container_ogm_append(bat_priv, ogm_buff, + ogm_buff_len, + BATADV_OGM_HLEN); + if (ret < 0) { + /* OGMs must be queued even when the buffer allocation for + * TVLVs failed. just fall back to the non-TVLV version + */ + ret = 0; + *ogm_buff_len = BATADV_OGM_HLEN; + } + + tvlv_len = ret; } batadv_ogm_packet = (struct batadv_ogm_packet *)(*ogm_buff); diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index e955b4940c72..d66ca77b1aaa 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -269,10 +269,10 @@ static void batadv_v_ogm_send_meshif(struct batadv_priv *bat_priv) struct batadv_hard_iface *hard_iface; struct batadv_ogm2_packet *ogm_packet; struct sk_buff *skb, *skb_tmp; - unsigned char *ogm_buff; + unsigned char **ogm_buff; struct list_head *iter; - int ogm_buff_len; - u16 tvlv_len = 0; + int *ogm_buff_len; + u16 tvlv_len; int ret; lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex); @@ -280,25 +280,27 @@ static void batadv_v_ogm_send_meshif(struct batadv_priv *bat_priv) if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) goto out; - ogm_buff = bat_priv->bat_v.ogm_buff; - ogm_buff_len = bat_priv->bat_v.ogm_buff_len; + ogm_buff = &bat_priv->bat_v.ogm_buff; + ogm_buff_len = &bat_priv->bat_v.ogm_buff_len; + /* tt changes have to be committed before the tvlv data is * appended as it may alter the tt tvlv container */ batadv_tt_local_commit_changes(bat_priv); - tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff, - &ogm_buff_len, - BATADV_OGM2_HLEN); + ret = batadv_tvlv_container_ogm_append(bat_priv, ogm_buff, + ogm_buff_len, + BATADV_OGM2_HLEN); + if (ret < 0) + goto reschedule; - bat_priv->bat_v.ogm_buff = ogm_buff; - bat_priv->bat_v.ogm_buff_len = ogm_buff_len; + tvlv_len = ret; - skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len); + skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + *ogm_buff_len); if (!skb) goto reschedule; skb_reserve(skb, ETH_HLEN); - skb_put_data(skb, ogm_buff, ogm_buff_len); + skb_put_data(skb, *ogm_buff, *ogm_buff_len); ogm_packet = (struct batadv_ogm2_packet *)skb->data; ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno)); diff --git a/net/batman-adv/tvlv.c b/net/batman-adv/tvlv.c index 8129a3f9c44d..46ed61dbf087 100644 --- a/net/batman-adv/tvlv.c +++ b/net/batman-adv/tvlv.c @@ -8,6 +8,7 @@ #include #include +#include #include #include #include @@ -306,9 +307,10 @@ static bool batadv_tvlv_realloc_packet_buff(unsigned char **packet_buff, * The ogm packet might be enlarged or shrunk depending on the current size * and the size of the to-be-appended tvlv containers. * - * Return: size of all appended tvlv containers in bytes. + * Return: size of all appended tvlv containers in bytes (max U16_MAX), negative + * if operation failed */ -u16 batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv, +int batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv, unsigned char **packet_buff, int *packet_buff_len, int packet_min_len) { @@ -316,6 +318,7 @@ u16 batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv, struct batadv_tvlv_hdr *tvlv_hdr; u16 tvlv_value_len; void *tvlv_value; + int tvlv_len_ret; bool ret; spin_lock_bh(&bat_priv->tvlv.container_list_lock); @@ -323,9 +326,12 @@ u16 batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv, ret = batadv_tvlv_realloc_packet_buff(packet_buff, packet_buff_len, packet_min_len, tvlv_value_len); - - if (!ret) + if (!ret) { + tvlv_len_ret = -ENOMEM; goto end; + } + + tvlv_len_ret = tvlv_value_len; if (!tvlv_value_len) goto end; @@ -344,7 +350,8 @@ u16 batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv, end: spin_unlock_bh(&bat_priv->tvlv.container_list_lock); - return tvlv_value_len; + + return tvlv_len_ret; } /** diff --git a/net/batman-adv/tvlv.h b/net/batman-adv/tvlv.h index e5697230d991..f96f6b3f44a0 100644 --- a/net/batman-adv/tvlv.h +++ b/net/batman-adv/tvlv.h @@ -16,7 +16,7 @@ void batadv_tvlv_container_register(struct batadv_priv *bat_priv, u8 type, u8 version, void *tvlv_value, u16 tvlv_value_len); -u16 batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv, +int batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv, unsigned char **packet_buff, int *packet_buff_len, int packet_min_len); void batadv_tvlv_ogm_receive(struct batadv_priv *bat_priv, -- cgit v1.2.3 From f50487e3566358b2b982b7801945e858c78ad9ab Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 9 May 2026 21:55:29 +0200 Subject: batman-adv: tvlv: reject oversized TVLV packets batadv_tvlv_container_ogm_append() builds a TVLV packet section from the tvlv.container_list. The total size of this section is computed by batadv_tvlv_container_list_size(), which sums the sizes of all registered containers. The return type and accumulator in batadv_tvlv_container_list_size() were u16. If the accumulated size exceeds U16_MAX, the value wraps around, causing the subsequent allocation in batadv_tvlv_container_ogm_append() to be undersized. The memcpy-style copy that follows would then write beyond the end of the allocated buffer, corrupting kernel memory. Fix this by widening the return type of batadv_tvlv_container_list_size() to size_t. In batadv_tvlv_container_ogm_append(), check the computed length against U16_MAX before proceeding, and bail out as if the allocation had failed when the limit is exceeded. Cc: stable@kernel.org Fixes: ef26157747d4 ("batman-adv: tvlv - basic infrastructure") Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Reviewed-by: Yuan Tan Signed-off-by: Sven Eckelmann --- net/batman-adv/tvlv.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/batman-adv/tvlv.c b/net/batman-adv/tvlv.c index 46ed61dbf087..cc6ac580c620 100644 --- a/net/batman-adv/tvlv.c +++ b/net/batman-adv/tvlv.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -160,10 +161,10 @@ batadv_tvlv_container_get(struct batadv_priv *bat_priv, u8 type, u8 version) * * Return: size of all currently registered tvlv containers in bytes. */ -static u16 batadv_tvlv_container_list_size(struct batadv_priv *bat_priv) +static size_t batadv_tvlv_container_list_size(struct batadv_priv *bat_priv) { struct batadv_tvlv_container *tvlv; - u16 tvlv_len = 0; + size_t tvlv_len = 0; lockdep_assert_held(&bat_priv->tvlv.container_list_lock); @@ -316,13 +317,17 @@ int batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv, { struct batadv_tvlv_container *tvlv; struct batadv_tvlv_hdr *tvlv_hdr; - u16 tvlv_value_len; + size_t tvlv_value_len; void *tvlv_value; int tvlv_len_ret; bool ret; spin_lock_bh(&bat_priv->tvlv.container_list_lock); tvlv_value_len = batadv_tvlv_container_list_size(bat_priv); + if (tvlv_value_len > U16_MAX) { + tvlv_len_ret = -E2BIG; + goto end; + } ret = batadv_tvlv_realloc_packet_buff(packet_buff, packet_buff_len, packet_min_len, tvlv_value_len); -- cgit v1.2.3 From 71dce47f0758537fff78fddb5fb0d4632d29b29f Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Wed, 13 May 2026 23:38:54 +0200 Subject: batman-adv: tp_meter: fix race condition in send error reporting batadv_tp_sender_shutdown() previously used two separate variables to track session state: sending (an atomic flag indicating whether the session was active) and reason (a plain enum storing the stop reason). This introduced a race window between the two writes: after sending was cleared to 0, batadv_tp_send() could observe the stopped state and call batadv_tp_sender_end() before reason was written, causing the wrong stop reason to be reported to the caller. Fix this by consolidating both variables into a single atomic send_result, which holds 0 while the session is running and the stop reason once it ends. Cc: stable@kernel.org Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation") Signed-off-by: Sven Eckelmann --- net/batman-adv/tp_meter.c | 40 +++++++++++++++++++++++++--------------- net/batman-adv/types.h | 10 +++++----- 2 files changed, 30 insertions(+), 20 deletions(-) (limited to 'net') diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index 1fd1526059d8..3ce6d9b2c9f3 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -413,11 +413,14 @@ static void batadv_tp_sender_cleanup(struct batadv_tp_vars *tp_vars) static void batadv_tp_sender_end(struct batadv_priv *bat_priv, struct batadv_tp_vars *tp_vars) { + enum batadv_tp_meter_reason reason; u32 session_cookie; + reason = atomic_read(&tp_vars->send_result); + batadv_dbg(BATADV_DBG_TP_METER, bat_priv, "Test towards %pM finished..shutting down (reason=%d)\n", - tp_vars->other_end, tp_vars->reason); + tp_vars->other_end, reason); batadv_dbg(BATADV_DBG_TP_METER, bat_priv, "Last timing stats: SRTT=%ums RTTVAR=%ums RTO=%ums\n", @@ -430,7 +433,7 @@ static void batadv_tp_sender_end(struct batadv_priv *bat_priv, session_cookie = batadv_tp_session_cookie(tp_vars->session, tp_vars->icmp_uid); - batadv_tp_batctl_notify(tp_vars->reason, + batadv_tp_batctl_notify(reason, tp_vars->other_end, bat_priv, tp_vars->start_time, @@ -446,10 +449,18 @@ static void batadv_tp_sender_end(struct batadv_priv *bat_priv, static void batadv_tp_sender_shutdown(struct batadv_tp_vars *tp_vars, enum batadv_tp_meter_reason reason) { - if (atomic_xchg(&tp_vars->sending, 0) != 1) - return; + atomic_cmpxchg(&tp_vars->send_result, 0, reason); +} - tp_vars->reason = reason; +/** + * batadv_tp_sender_stopped() - check if tp session was stopped with reason + * @tp_vars: the private data of the current TP meter session + * + * Return: whether stop reason was found + */ +static bool batadv_tp_sender_stopped(struct batadv_tp_vars *tp_vars) +{ + return atomic_read(&tp_vars->send_result) != 0; } /** @@ -479,7 +490,7 @@ static void batadv_tp_reset_sender_timer(struct batadv_tp_vars *tp_vars) /* most of the time this function is invoked while normal packet * reception... */ - if (unlikely(atomic_read(&tp_vars->sending) == 0)) + if (unlikely(batadv_tp_sender_stopped(tp_vars))) /* timer ref will be dropped in batadv_tp_sender_cleanup */ return; @@ -499,7 +510,7 @@ static void batadv_tp_sender_timeout(struct timer_list *t) struct batadv_tp_vars *tp_vars = timer_container_of(tp_vars, t, timer); struct batadv_priv *bat_priv = tp_vars->bat_priv; - if (atomic_read(&tp_vars->sending) == 0) + if (batadv_tp_sender_stopped(tp_vars)) return; /* if the user waited long enough...shutdown the test */ @@ -661,7 +672,7 @@ static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, if (unlikely(tp_vars->role != BATADV_TP_SENDER)) goto out; - if (unlikely(atomic_read(&tp_vars->sending) == 0)) + if (unlikely(batadv_tp_sender_stopped(tp_vars))) goto out; /* old ACK? silently drop it.. */ @@ -827,21 +838,21 @@ static int batadv_tp_send(void *arg) if (unlikely(tp_vars->role != BATADV_TP_SENDER)) { err = BATADV_TP_REASON_DST_UNREACHABLE; - tp_vars->reason = err; + batadv_tp_sender_shutdown(tp_vars, err); goto out; } orig_node = batadv_orig_hash_find(bat_priv, tp_vars->other_end); if (unlikely(!orig_node)) { err = BATADV_TP_REASON_DST_UNREACHABLE; - tp_vars->reason = err; + batadv_tp_sender_shutdown(tp_vars, err); goto out; } primary_if = batadv_primary_if_get_selected(bat_priv); if (unlikely(!primary_if)) { err = BATADV_TP_REASON_DST_UNREACHABLE; - tp_vars->reason = err; + batadv_tp_sender_shutdown(tp_vars, err); goto out; } @@ -860,7 +871,7 @@ static int batadv_tp_send(void *arg) queue_delayed_work(batadv_event_workqueue, &tp_vars->finish_work, msecs_to_jiffies(tp_vars->test_length)); - while (atomic_read(&tp_vars->sending) != 0) { + while (!batadv_tp_sender_stopped(tp_vars)) { if (unlikely(!batadv_tp_avail(tp_vars, payload_len))) { batadv_tp_wait_available(tp_vars, payload_len); continue; @@ -883,8 +894,7 @@ static int batadv_tp_send(void *arg) "Meter: %s() cannot send packets (%d)\n", __func__, err); /* ensure nobody else tries to stop the thread now */ - if (atomic_xchg(&tp_vars->sending, 0) == 1) - tp_vars->reason = err; + batadv_tp_sender_shutdown(tp_vars, err); break; } @@ -1006,7 +1016,7 @@ void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst, ether_addr_copy(tp_vars->other_end, dst); kref_init(&tp_vars->refcount); tp_vars->role = BATADV_TP_SENDER; - atomic_set(&tp_vars->sending, 1); + atomic_set(&tp_vars->send_result, 0); memcpy(tp_vars->session, session_id, sizeof(session_id)); tp_vars->icmp_uid = icmp_uid; diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index c8c3e8064f00..fb0e4cb89d79 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1320,15 +1320,15 @@ struct batadv_tp_vars { /** @role: receiver/sender modi */ enum batadv_tp_meter_role role; - /** @sending: sending binary semaphore: 1 if sending, 0 is not */ - atomic_t sending; + /** + * @send_result: 0 when sending is ongoing and otherwise + * enum batadv_tp_meter_reason + */ + atomic_t send_result; /** @receiving: receiving binary semaphore: 1 if receiving, 0 is not */ atomic_t receiving; - /** @reason: reason for a stopped session */ - enum batadv_tp_meter_reason reason; - /** @finish_work: work item for the finishing procedure */ struct delayed_work finish_work; -- cgit v1.2.3 From ff24f2ecfd94c07a2b89bac497433e3b23271cac Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 16 May 2026 12:33:41 +0200 Subject: batman-adv: tp_meter: avoid role confusion in tp_list Session lookups in tp_list matched only on destination address (and optionally session ID), leaving role validation to the caller. If two sessions with the same other_end coexisted (one as sender, one as receiver) a lookup could silently return the wrong one, causing the caller's role to bail out early, potentially skipping necessary cleanup. Move the role check into the lookup functions themselves so the correct entry is always returned, or none at all. Since batadv_tp_start() legitimately needs to detect any active session to a destination regardless of role, introduce a dedicated helper for that case rather than bending the existing lookup semantics. Cc: stable@kernel.org Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation") Signed-off-by: Sven Eckelmann --- net/batman-adv/tp_meter.c | 59 +++++++++++++++++++++++++++++------------------ 1 file changed, 36 insertions(+), 23 deletions(-) (limited to 'net') diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index 3ce6d9b2c9f3..0fc4ca78e84e 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -255,6 +255,7 @@ static void batadv_tp_batctl_error_notify(enum batadv_tp_meter_reason reason, * batadv_tp_list_find() - find a tp_vars object in the global list * @bat_priv: the bat priv with all the mesh interface information * @dst: the other endpoint MAC address to look for + * @role: role of the session * * Look for a tp_vars object matching dst as end_point and return it after * having increment the refcounter. Return NULL is not found @@ -262,7 +263,8 @@ static void batadv_tp_batctl_error_notify(enum batadv_tp_meter_reason reason, * Return: matching tp_vars or NULL when no tp_vars with @dst was found */ static struct batadv_tp_vars *batadv_tp_list_find(struct batadv_priv *bat_priv, - const u8 *dst) + const u8 *dst, + enum batadv_tp_meter_role role) { struct batadv_tp_vars *pos, *tp_vars = NULL; @@ -271,6 +273,9 @@ static struct batadv_tp_vars *batadv_tp_list_find(struct batadv_priv *bat_priv, if (!batadv_compare_eth(pos->other_end, dst)) continue; + if (pos->role != role) + continue; + /* most of the time this function is invoked during the normal * process..it makes sens to pay more when the session is * finished and to speed the process up during the measurement @@ -286,12 +291,33 @@ static struct batadv_tp_vars *batadv_tp_list_find(struct batadv_priv *bat_priv, return tp_vars; } +/** + * batadv_tp_list_active() - check if session from/to destination is ongoing + * @bat_priv: the bat priv with all the mesh interface information + * @dst: the other endpoint MAC address to look for + * + * Return: if matching session with @dst was found + */ +static bool batadv_tp_list_active(struct batadv_priv *bat_priv, const u8 *dst) + __must_hold(&bat_priv->tp_list_lock) +{ + struct batadv_tp_vars *tp_vars; + + hlist_for_each_entry_rcu(tp_vars, &bat_priv->tp_list, list) { + if (batadv_compare_eth(tp_vars->other_end, dst)) + return true; + } + + return false; +} + /** * batadv_tp_list_find_session() - find tp_vars session object in the global * list * @bat_priv: the bat priv with all the mesh interface information * @dst: the other endpoint MAC address to look for * @session: session identifier + * @role: role of the session * * Look for a tp_vars object matching dst as end_point, session as tp meter * session and return it after having increment the refcounter. Return NULL @@ -301,7 +327,7 @@ static struct batadv_tp_vars *batadv_tp_list_find(struct batadv_priv *bat_priv, */ static struct batadv_tp_vars * batadv_tp_list_find_session(struct batadv_priv *bat_priv, const u8 *dst, - const u8 *session) + const u8 *session, enum batadv_tp_meter_role role) { struct batadv_tp_vars *pos, *tp_vars = NULL; @@ -313,6 +339,9 @@ batadv_tp_list_find_session(struct batadv_priv *bat_priv, const u8 *dst, if (memcmp(pos->session, session, sizeof(pos->session)) != 0) continue; + if (pos->role != role) + continue; + /* most of the time this function is invoked during the normal * process..it makes sense to pay more when the session is * finished and to speed the process up during the measurement @@ -665,13 +694,10 @@ static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, /* find the tp_vars */ tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, - icmp->session); + icmp->session, BATADV_TP_SENDER); if (unlikely(!tp_vars)) return; - if (unlikely(tp_vars->role != BATADV_TP_SENDER)) - goto out; - if (unlikely(batadv_tp_sender_stopped(tp_vars))) goto out; @@ -980,10 +1006,8 @@ void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst, return; } - tp_vars = batadv_tp_list_find(bat_priv, dst); - if (tp_vars) { + if (batadv_tp_list_active(bat_priv, dst)) { spin_unlock_bh(&bat_priv->tp_list_lock); - batadv_tp_vars_put(tp_vars); batadv_dbg(BATADV_DBG_TP_METER, bat_priv, "Meter: test to or from the same node already ongoing, aborting\n"); batadv_tp_batctl_error_notify(BATADV_TP_REASON_ALREADY_ONGOING, @@ -1104,18 +1128,14 @@ void batadv_tp_stop(struct batadv_priv *bat_priv, const u8 *dst, if (!orig_node) return; - tp_vars = batadv_tp_list_find(bat_priv, orig_node->orig); + tp_vars = batadv_tp_list_find(bat_priv, orig_node->orig, BATADV_TP_SENDER); if (!tp_vars) { batadv_dbg(BATADV_DBG_TP_METER, bat_priv, "Meter: trying to interrupt an already over connection\n"); goto out_put_orig_node; } - if (unlikely(tp_vars->role != BATADV_TP_SENDER)) - goto out_put_tp_vars; - batadv_tp_sender_shutdown(tp_vars, return_value); -out_put_tp_vars: batadv_tp_vars_put(tp_vars); out_put_orig_node: batadv_orig_node_put(orig_node); @@ -1371,7 +1391,7 @@ batadv_tp_init_recv(struct batadv_priv *bat_priv, goto out_unlock; tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, - icmp->session); + icmp->session, BATADV_TP_RECEIVER); if (tp_vars) goto out_unlock; @@ -1442,7 +1462,7 @@ static void batadv_tp_recv_msg(struct batadv_priv *bat_priv, } } else { tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, - icmp->session); + icmp->session, BATADV_TP_RECEIVER); if (!tp_vars) { batadv_dbg(BATADV_DBG_TP_METER, bat_priv, "Unexpected packet from %pM!\n", @@ -1451,13 +1471,6 @@ static void batadv_tp_recv_msg(struct batadv_priv *bat_priv, } } - if (unlikely(tp_vars->role != BATADV_TP_RECEIVER)) { - batadv_dbg(BATADV_DBG_TP_METER, bat_priv, - "Meter: dropping packet: not expected (role=%u)\n", - tp_vars->role); - goto out; - } - tp_vars->last_recv_time = jiffies; /* if the packet is a duplicate, it may be the case that an ACK has been -- cgit v1.2.3 From 20c2d6a20ca936f5aaa6dd40f73f262ac45c87cc Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Thu, 14 May 2026 19:22:02 +0200 Subject: batman-adv: mcast: fix use-after-free in orig_node RCU release MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit batadv_mcast_purge_orig() removes entries from RCU-protected hlists but does not wait for an RCU grace period before returning. Concurrent RCU readers may still accesses references to those entries at the point of removal. RCU-protected readers trying to operate on entries like orig->mcast_want_all_ipv6_node will then access already freed memory. Fix this by moving batadv_mcast_purge_orig() to batadv_orig_node_release(), just before the call_rcu() invocation. This ensures RCU readers that were active at purge time have drained before the orig_node memory is reclaimed. Cc: stable@kernel.org Fixes: ab49886e3da7 ("batman-adv: Add IPv4 link-local/IPv6-ll-all-nodes multicast support") Acked-by: Linus Lüssing Signed-off-by: Sven Eckelmann --- net/batman-adv/originator.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index b3468ccab535..ad4921b659d9 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -835,8 +835,6 @@ static void batadv_orig_node_free_rcu(struct rcu_head *rcu) orig_node = container_of(rcu, struct batadv_orig_node, rcu); - batadv_mcast_purge_orig(orig_node); - batadv_frag_purge_orig(orig_node, NULL); kfree(orig_node->tt_buff); @@ -887,6 +885,8 @@ void batadv_orig_node_release(struct kref *ref) } spin_unlock_bh(&orig_node->vlan_list_lock); + batadv_mcast_purge_orig(orig_node); + call_rcu(&orig_node->rcu, batadv_orig_node_free_rcu); } -- cgit v1.2.3 From aa3153bd139a6c48667dcd02608d3b2c80bff02c Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Fri, 15 May 2026 22:00:40 +0200 Subject: batman-adv: iv: recover OGM scheduling after forward packet error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When batadv_iv_ogm_schedule_buff() fails to allocate and queue a forward packet for OGM transmission, the work item that drives periodic OGM scheduling is never re-armed. This silently halts transmission of the node's own OGMs on the affected interface — only OGMs from other peers continue to be aggregated and forwarded. Fix this by tracking whether batadv_iv_ogm_queue_add() (and transitively batadv_iv_ogm_aggregate_new()) successfully scheduled a forward packet. When scheduling fails, batadv_iv_ogm_schedule_buff() falls back to queuing a dedicated recovery work item (reschedule_work) that fires after one originator interval and calls batadv_iv_ogm_schedule() again. Cc: stable@kernel.org Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") Signed-off-by: Sven Eckelmann --- net/batman-adv/bat_iv_ogm.c | 76 +++++++++++++++++++++++++++++++++------------ net/batman-adv/types.h | 3 ++ 2 files changed, 60 insertions(+), 19 deletions(-) (limited to 'net') diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 7ad26128b5f7..b8b1b997960a 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -224,6 +224,8 @@ static void batadv_iv_ogm_iface_disable(struct batadv_hard_iface *hard_iface) hard_iface->bat_iv.ogm_buff = NULL; mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex); + + cancel_delayed_work_sync(&hard_iface->bat_iv.reschedule_work); } static void batadv_iv_ogm_iface_update_mac(struct batadv_hard_iface *hard_iface) @@ -536,8 +538,10 @@ out: * @if_incoming: interface where the packet was received * @if_outgoing: interface for which the retransmission should be considered * @own_packet: true if it is a self-generated ogm + * + * Return: whether forward packet was scheduled */ -static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, +static bool batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, int packet_len, unsigned long send_time, bool direct_link, struct batadv_hard_iface *if_incoming, @@ -561,13 +565,13 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, skb = netdev_alloc_skb_ip_align(NULL, skb_size); if (!skb) - return; + return false; forw_packet_aggr = batadv_forw_packet_alloc(if_incoming, if_outgoing, queue_left, bat_priv, skb); if (!forw_packet_aggr) { kfree_skb(skb); - return; + return false; } forw_packet_aggr->skb->priority = TC_PRIO_CONTROL; @@ -590,6 +594,8 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, batadv_iv_send_outstanding_bat_ogm_packet); batadv_forw_packet_ogmv1_queue(bat_priv, forw_packet_aggr, send_time); + + return true; } /* aggregate a new packet into the existing ogm packet */ @@ -617,8 +623,10 @@ static void batadv_iv_ogm_aggregate(struct batadv_forw_packet *forw_packet_aggr, * @if_outgoing: interface for which the retransmission should be considered * @own_packet: true if it is a self-generated ogm * @send_time: timestamp (jiffies) when the packet is to be sent + * + * Return: whether forward packet was scheduled */ -static void batadv_iv_ogm_queue_add(struct batadv_priv *bat_priv, +static bool batadv_iv_ogm_queue_add(struct batadv_priv *bat_priv, unsigned char *packet_buff, int packet_len, struct batadv_hard_iface *if_incoming, @@ -670,14 +678,16 @@ static void batadv_iv_ogm_queue_add(struct batadv_priv *bat_priv, if (!own_packet && atomic_read(&bat_priv->aggregated_ogms)) send_time += max_aggregation_jiffies; - batadv_iv_ogm_aggregate_new(packet_buff, packet_len, - send_time, direct_link, - if_incoming, if_outgoing, - own_packet); + return batadv_iv_ogm_aggregate_new(packet_buff, packet_len, + send_time, direct_link, + if_incoming, if_outgoing, + own_packet); } else { batadv_iv_ogm_aggregate(forw_packet_aggr, packet_buff, packet_len, direct_link); spin_unlock_bh(&bat_priv->forw_bat_list_lock); + + return true; } } @@ -790,6 +800,8 @@ static void batadv_iv_ogm_schedule_buff(struct batadv_hard_iface *hard_iface) u32 seqno; u16 tvlv_len = 0; unsigned long send_time; + bool reschedule = false; + bool scheduled; int ret; lockdep_assert_held(&hard_iface->bat_iv.ogm_buff_mutex); @@ -818,11 +830,8 @@ static void batadv_iv_ogm_schedule_buff(struct batadv_hard_iface *hard_iface) ogm_buff_len, BATADV_OGM_HLEN); if (ret < 0) { - /* OGMs must be queued even when the buffer allocation for - * TVLVs failed. just fall back to the non-TVLV version - */ - ret = 0; - *ogm_buff_len = BATADV_OGM_HLEN; + reschedule = true; + goto out; } tvlv_len = ret; @@ -844,8 +853,11 @@ static void batadv_iv_ogm_schedule_buff(struct batadv_hard_iface *hard_iface) /* OGMs from secondary interfaces are only scheduled on their * respective interfaces. */ - batadv_iv_ogm_queue_add(bat_priv, *ogm_buff, *ogm_buff_len, - hard_iface, hard_iface, 1, send_time); + scheduled = batadv_iv_ogm_queue_add(bat_priv, *ogm_buff, *ogm_buff_len, + hard_iface, hard_iface, 1, send_time); + if (!scheduled) + reschedule = true; + goto out; } @@ -857,15 +869,28 @@ static void batadv_iv_ogm_schedule_buff(struct batadv_hard_iface *hard_iface) if (!kref_get_unless_zero(&tmp_hard_iface->refcount)) continue; - batadv_iv_ogm_queue_add(bat_priv, *ogm_buff, - *ogm_buff_len, hard_iface, - tmp_hard_iface, 1, send_time); - + scheduled = batadv_iv_ogm_queue_add(bat_priv, *ogm_buff, + *ogm_buff_len, hard_iface, + tmp_hard_iface, 1, send_time); batadv_hardif_put(tmp_hard_iface); + + if (!scheduled && tmp_hard_iface == hard_iface) + reschedule = true; } rcu_read_unlock(); out: + if (reschedule) { + /* there was a failure scheduling the own forward packet. + * as result, the batadv_iv_send_outstanding_bat_ogm_packet() + * work item is no longer scheduled. it is therefore necessary + * to reschedule it manually + */ + queue_delayed_work(batadv_event_workqueue, + &hard_iface->bat_iv.reschedule_work, + msecs_to_jiffies(atomic_read(&bat_priv->orig_interval))); + } + batadv_hardif_put(primary_if); } @@ -880,6 +905,17 @@ static void batadv_iv_ogm_schedule(struct batadv_hard_iface *hard_iface) mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex); } +static void batadv_iv_ogm_reschedule(struct work_struct *work) +{ + struct delayed_work *delayed_work = to_delayed_work(work); + struct batadv_hard_iface *hard_iface; + + hard_iface = container_of(delayed_work, + struct batadv_hard_iface, + bat_iv.reschedule_work); + batadv_iv_ogm_schedule(hard_iface); +} + /** * batadv_iv_orig_ifinfo_sum() - Get bcast_own sum for originator over interface * @orig_node: originator which reproadcasted the OGMs directly @@ -2272,6 +2308,8 @@ batadv_iv_ogm_neigh_is_sob(struct batadv_neigh_node *neigh1, static void batadv_iv_iface_enabled(struct batadv_hard_iface *hard_iface) { + INIT_DELAYED_WORK(&hard_iface->bat_iv.reschedule_work, batadv_iv_ogm_reschedule); + /* begin scheduling originator messages on that interface */ batadv_iv_ogm_schedule(hard_iface); } diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index fb0e4cb89d79..821ada05d86a 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -83,6 +83,9 @@ struct batadv_hard_iface_bat_iv { /** @ogm_seqno: OGM sequence number - used to identify each OGM */ atomic_t ogm_seqno; + /** @reschedule_work: recover OGM schedule after schedule error */ + struct delayed_work reschedule_work; + /** @ogm_buff_mutex: lock protecting ogm_buff and ogm_buff_len */ struct mutex ogm_buff_mutex; }; -- cgit v1.2.3 From 0459430add32ea41f3e2ef9351610e6d33627a6b Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sun, 10 May 2026 11:43:20 +0200 Subject: batman-adv: bla: fix report_work leak on backbone_gw purge batadv_bla_purge_backbone_gw() removes stale backbone gateway entries, but fails to properly handle their associated report_work: - If report_work is running, the purge must wait for it to finish before freeing the backbone_gw, otherwise the worker may access freed memory (e.g. bat_priv). - If report_work is pending, the purge must cancel it and release the reference held for that pending work item. The previous implementation called hlist_for_each_entry_safe() inside a spin_lock_bh() section, but cancel_work_sync() may sleep and therefore cannot be called from within a spinlock-protected region. Restructure the loop to handle one entry per spinlock critical section: acquire the lock, find the next entry to purge, remove it from the hash list, then release the lock before calling cancel_work_sync() and dropping the hash_entry reference. Repeat until no more entries require purging. Cc: stable@kernel.org Fixes: 23721387c409 ("batman-adv: add basic bridge loop avoidance code") Reviewed-by: Simon Wunderlich Signed-off-by: Sven Eckelmann --- net/batman-adv/bridge_loop_avoidance.c | 54 ++++++++++++++++++++++------------ 1 file changed, 35 insertions(+), 19 deletions(-) (limited to 'net') diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index cec11f1251d6..df1dfdf4a1a1 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -1224,6 +1224,7 @@ static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now) struct hlist_head *head; struct batadv_hashtable *hash; spinlock_t *list_lock; /* protects write access to the hash lists */ + bool purged; int i; hash = bat_priv->bla.backbone_hash; @@ -1234,30 +1235,45 @@ static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now) head = &hash->table[i]; list_lock = &hash->list_locks[i]; - spin_lock_bh(list_lock); - hlist_for_each_entry_safe(backbone_gw, node_tmp, - head, hash_entry) { - if (now) - goto purge_now; - if (!batadv_has_timed_out(backbone_gw->lasttime, - BATADV_BLA_BACKBONE_TIMEOUT)) - continue; + do { + purged = false; - batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv, - "%s(): backbone gw %pM timed out\n", - __func__, backbone_gw->orig); + spin_lock_bh(list_lock); + hlist_for_each_entry_safe(backbone_gw, node_tmp, + head, hash_entry) { + if (now) + goto purge_now; + if (!batadv_has_timed_out(backbone_gw->lasttime, + BATADV_BLA_BACKBONE_TIMEOUT)) + continue; + + batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv, + "%s(): backbone gw %pM timed out\n", + __func__, backbone_gw->orig); purge_now: - /* don't wait for the pending request anymore */ - if (atomic_read(&backbone_gw->request_sent)) - atomic_dec(&bat_priv->bla.num_requests); + purged = true; - batadv_bla_del_backbone_claims(backbone_gw); + /* don't wait for the pending request anymore */ + if (atomic_read(&backbone_gw->request_sent)) + atomic_dec(&bat_priv->bla.num_requests); - hlist_del_rcu(&backbone_gw->hash_entry); - batadv_backbone_gw_put(backbone_gw); - } - spin_unlock_bh(list_lock); + batadv_bla_del_backbone_claims(backbone_gw); + + hlist_del_rcu(&backbone_gw->hash_entry); + break; + } + spin_unlock_bh(list_lock); + + if (purged) { + /* reference for pending report_work */ + if (cancel_work_sync(&backbone_gw->report_work)) + batadv_backbone_gw_put(backbone_gw); + + /* reference for hash_entry */ + batadv_backbone_gw_put(backbone_gw); + } + } while (purged); } } -- cgit v1.2.3 From 83ab69bd12b80f6ea169c8bea6977701b53a043d Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Tue, 12 May 2026 09:13:31 +0200 Subject: batman-adv: bla: avoid double decrement of bla.num_requests The bla.num_requests is increased when no request_sent was in progress. And it is decremented in various places (announcement was received, backbone is purged, periodic work). But the check if the request_sent is actually set to a specific state and the atomic_dec/_inc are not safe because they are not atomic (TOCTOU) and multiple such code portions can run concurrently. At the same time, it is necessary to modify request_sent (state) and bla.num_requests atomically. Otherwise batadv_bla_send_request() might set request_sent to 1 and is interrupted. batadv_handle_announce() can then set request_sent back to 0 and decrement num_requests before batadv_bla_send_request() incremented it. The two operations must therefore be locked. And since state (request_sent) and wait_periods are only accessed inside this lock, they can be converted to simpler datatypes. And to avoid that the bla.num_requests is touched by a parallel running context with a valid backbone_gw reference after batadv_bla_purge_backbone_gw() ran, a third state "stopped" is required to correctly signal that a backbone_gw is in the state of being cleaned up. Cc: stable@kernel.org Fixes: 23721387c409 ("batman-adv: add basic bridge loop avoidance code") Signed-off-by: Sven Eckelmann --- net/batman-adv/bridge_loop_avoidance.c | 51 +++++++++++++++++++++++----------- net/batman-adv/mesh-interface.c | 1 + net/batman-adv/types.h | 39 ++++++++++++++++++++------ 3 files changed, 67 insertions(+), 24 deletions(-) (limited to 'net') diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index df1dfdf4a1a1..1bef12e659cb 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -514,8 +514,8 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, const u8 *orig, entry->crc = BATADV_BLA_CRC_INIT; entry->bat_priv = bat_priv; spin_lock_init(&entry->crc_lock); - atomic_set(&entry->request_sent, 0); - atomic_set(&entry->wait_periods, 0); + entry->state = BATADV_BLA_BACKBONE_GW_SYNCED; + entry->wait_periods = 0; ether_addr_copy(entry->orig, orig); INIT_WORK(&entry->report_work, batadv_bla_loopdetect_report); kref_init(&entry->refcount); @@ -544,9 +544,13 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, const u8 *orig, batadv_bla_send_announce(bat_priv, entry); /* this will be decreased in the worker thread */ - atomic_inc(&entry->request_sent); - atomic_set(&entry->wait_periods, BATADV_BLA_WAIT_PERIODS); - atomic_inc(&bat_priv->bla.num_requests); + spin_lock_bh(&bat_priv->bla.num_requests_lock); + if (entry->state == BATADV_BLA_BACKBONE_GW_SYNCED) { + entry->state = BATADV_BLA_BACKBONE_GW_UNSYNCED; + entry->wait_periods = BATADV_BLA_WAIT_PERIODS; + atomic_inc(&bat_priv->bla.num_requests); + } + spin_unlock_bh(&bat_priv->bla.num_requests_lock); } return entry; @@ -649,10 +653,12 @@ static void batadv_bla_send_request(struct batadv_bla_backbone_gw *backbone_gw) backbone_gw->vid, BATADV_CLAIM_TYPE_REQUEST); /* no local broadcasts should be sent or received, for now. */ - if (!atomic_read(&backbone_gw->request_sent)) { + spin_lock_bh(&backbone_gw->bat_priv->bla.num_requests_lock); + if (backbone_gw->state == BATADV_BLA_BACKBONE_GW_SYNCED) { + backbone_gw->state = BATADV_BLA_BACKBONE_GW_UNSYNCED; atomic_inc(&backbone_gw->bat_priv->bla.num_requests); - atomic_set(&backbone_gw->request_sent, 1); } + spin_unlock_bh(&backbone_gw->bat_priv->bla.num_requests_lock); } /** @@ -873,10 +879,12 @@ static bool batadv_handle_announce(struct batadv_priv *bat_priv, u8 *an_addr, /* if we have sent a request and the crc was OK, * we can allow traffic again. */ - if (atomic_read(&backbone_gw->request_sent)) { + spin_lock_bh(&bat_priv->bla.num_requests_lock); + if (backbone_gw->state == BATADV_BLA_BACKBONE_GW_UNSYNCED) { + backbone_gw->state = BATADV_BLA_BACKBONE_GW_SYNCED; atomic_dec(&backbone_gw->bat_priv->bla.num_requests); - atomic_set(&backbone_gw->request_sent, 0); } + spin_unlock_bh(&bat_priv->bla.num_requests_lock); } batadv_backbone_gw_put(backbone_gw); @@ -1255,9 +1263,13 @@ purge_now: purged = true; /* don't wait for the pending request anymore */ - if (atomic_read(&backbone_gw->request_sent)) + spin_lock_bh(&bat_priv->bla.num_requests_lock); + if (backbone_gw->state == BATADV_BLA_BACKBONE_GW_UNSYNCED) atomic_dec(&bat_priv->bla.num_requests); + backbone_gw->state = BATADV_BLA_BACKBONE_GW_STOPPED; + spin_unlock_bh(&bat_priv->bla.num_requests_lock); + batadv_bla_del_backbone_claims(backbone_gw); hlist_del_rcu(&backbone_gw->hash_entry); @@ -1508,7 +1520,7 @@ static void batadv_bla_periodic_work(struct work_struct *work) batadv_bla_send_loopdetect(bat_priv, backbone_gw); - /* request_sent is only set after creation to avoid + /* state is only set to unsynced after creation to avoid * problems when we are not yet known as backbone gw * in the backbone. * @@ -1517,14 +1529,21 @@ static void batadv_bla_periodic_work(struct work_struct *work) * some grace time. */ - if (atomic_read(&backbone_gw->request_sent) == 0) - continue; + spin_lock_bh(&bat_priv->bla.num_requests_lock); + if (backbone_gw->state != BATADV_BLA_BACKBONE_GW_UNSYNCED) + goto unlock_next; - if (!atomic_dec_and_test(&backbone_gw->wait_periods)) - continue; + if (backbone_gw->wait_periods > 0) + backbone_gw->wait_periods--; + + if (backbone_gw->wait_periods > 0) + goto unlock_next; + backbone_gw->state = BATADV_BLA_BACKBONE_GW_SYNCED; atomic_dec(&backbone_gw->bat_priv->bla.num_requests); - atomic_set(&backbone_gw->request_sent, 0); + +unlock_next: + spin_unlock_bh(&bat_priv->bla.num_requests_lock); } rcu_read_unlock(); } diff --git a/net/batman-adv/mesh-interface.c b/net/batman-adv/mesh-interface.c index 56ca1c1b83f2..e7aa45bc6b7a 100644 --- a/net/batman-adv/mesh-interface.c +++ b/net/batman-adv/mesh-interface.c @@ -787,6 +787,7 @@ static int batadv_meshif_init_late(struct net_device *dev) atomic_set(&bat_priv->tt.ogm_append_cnt, 0); #ifdef CONFIG_BATMAN_ADV_BLA atomic_set(&bat_priv->bla.num_requests, 0); + spin_lock_init(&bat_priv->bla.num_requests_lock); #endif atomic_set(&bat_priv->tp_num, 0); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 821ada05d86a..a01ee46d97f3 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1026,6 +1026,12 @@ struct batadv_priv_bla { /** @num_requests: number of bla requests in flight */ atomic_t num_requests; + /** + * @num_requests_lock: locks update num_requests + + * batadv_backbone_gw::state + batadv_backbone_gw::wait_periods update + */ + spinlock_t num_requests_lock; + /** * @claim_hash: hash table containing mesh nodes this host has claimed */ @@ -1672,6 +1678,27 @@ struct batadv_priv { #ifdef CONFIG_BATMAN_ADV_BLA +enum batadv_bla_backbone_gw_state { + /** + * @BATADV_BLA_BACKBONE_GW_STOPPED: backbone gw is being removed + * and it must not longer work on requests + */ + BATADV_BLA_BACKBONE_GW_STOPPED, + + /** + * @BATADV_BLA_BACKBONE_GW_UNSYNCED: backbone was detected out + * of sync and a request was send. No traffic is forwarded until the + * situation is resolved + */ + BATADV_BLA_BACKBONE_GW_UNSYNCED, + + /** + * @BATADV_BLA_BACKBONE_GW_SYNCED: backbone is consider to be in + * sync. traffic can be forwarded + */ + BATADV_BLA_BACKBONE_GW_SYNCED, +}; + /** * struct batadv_bla_backbone_gw - batman-adv gateway bridged into the LAN */ @@ -1697,16 +1724,12 @@ struct batadv_bla_backbone_gw { /** * @wait_periods: grace time for bridge forward delays and bla group * forming at bootup phase - no bcast traffic is formwared until it has - * elapsed + * elapsed. Must only be access with num_requests_lock. */ - atomic_t wait_periods; + u8 wait_periods; - /** - * @request_sent: if this bool is set to true we are out of sync with - * this backbone gateway - no bcast traffic is formwared until the - * situation was resolved - */ - atomic_t request_sent; + /** @state: sync state. Must only be access with num_requests_lock. */ + enum batadv_bla_backbone_gw_state state; /** @crc: crc16 checksum over all claims */ u16 crc; -- cgit v1.2.3 From f80d3d98d2ff78d9e2fe5d68b1f45948c4f7bd24 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Tue, 19 May 2026 09:23:49 +0200 Subject: batman-adv: bla: avoid NULL-ptr deref for claim via dropped interface Without rtnl_lock held, a hardif might be retrieved as primary interface of a meshif, but then (while operating on this interface) getting decoupled from the mesh interface. In this case, the meshif still exists but the pointer from the primary hardif to the meshif is set to NULL. The mesh_iface must be checked first to be non-NULL before continuing to send an ARP request using meshif. Cc: stable@kernel.org Fixes: 23721387c409 ("batman-adv: add basic bridge loop avoidance code") Reported-by: Ido Schimmel Reported-by: syzbot+9fdcc9f05a98a540b816@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9fdcc9f05a98a540b816 Signed-off-by: Sven Eckelmann --- net/batman-adv/bridge_loop_avoidance.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 1bef12e659cb..ffe854018bd3 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -356,12 +356,14 @@ static void batadv_bla_send_claim(struct batadv_priv *bat_priv, const u8 *mac, sizeof(local_claim_dest)); local_claim_dest.type = claimtype; - mesh_iface = primary_if->mesh_iface; + mesh_iface = READ_ONCE(primary_if->mesh_iface); + if (!mesh_iface) + goto out; skb = arp_create(ARPOP_REPLY, ETH_P_ARP, /* IP DST: 0.0.0.0 */ zeroip, - primary_if->mesh_iface, + mesh_iface, /* IP SRC: 0.0.0.0 */ zeroip, /* Ethernet DST: Broadcast */ -- cgit v1.2.3 From 50c2d91c5dfa0e465826ec1f8dbad9cdc254bd85 Mon Sep 17 00:00:00 2001 From: Shardul Bankar Date: Fri, 15 May 2026 06:27:32 +0200 Subject: mptcp: do not drop partial packets When a packet arrives with map_seq < ack_seq < end_seq, the beginning of the packet has already been acknowledged but the end contains new data. Currently the entire packet is dropped as "old data," forcing the sender to retransmit. Instead, skip the already-acked bytes by adjusting the skb offset and enqueue only the new portion. Update bytes_received and ack_seq to reflect the new data consumed. A previous attempt at this fix has been sent by Paolo Abeni [1], but had issues [2]: it also added a zero-window check and changed rcv_wnd_sent initialization, which caused test regressions. This version addresses only the partial packet handling without modifying receive window accounting. Fixes: ab174ad8ef76 ("mptcp: move ooo skbs into msk out of order queue.") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/c9b426a4e163aa3c4fe8b80c79f1a610f47ae7d8.1763075056.git.pabeni@redhat.com [1] Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/600 [2] Signed-off-by: Shardul Bankar [pabeni@redhat.com: update map] Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260515-net-mptcp-misc-fixes-7-1-rc4-v2-1-701e96419f2f@kernel.org Signed-off-by: Paolo Abeni --- net/mptcp/protocol.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) (limited to 'net') diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 4546a8b09884..859df49e16dc 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -397,12 +397,26 @@ static bool __mptcp_move_skb(struct sock *sk, struct sk_buff *skb) return false; } - /* old data, keep it simple and drop the whole pkt, sender - * will retransmit as needed, if needed. + /* Completely old data? */ + if (!after64(MPTCP_SKB_CB(skb)->end_seq, msk->ack_seq)) { + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); + mptcp_drop(sk, skb); + return false; + } + + /* Partial packet: map_seq < ack_seq < end_seq. + * Skip the already-acked bytes and enqueue the new data. */ - MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); - mptcp_drop(sk, skb); - return false; + copy_len = MPTCP_SKB_CB(skb)->end_seq - msk->ack_seq; + MPTCP_SKB_CB(skb)->offset += msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq; + MPTCP_SKB_CB(skb)->map_seq += msk->ack_seq - + MPTCP_SKB_CB(skb)->map_seq; + msk->bytes_received += copy_len; + WRITE_ONCE(msk->ack_seq, msk->ack_seq + copy_len); + + skb_set_owner_r(skb, sk); + __skb_queue_tail(&sk->sk_receive_queue, skb); + return true; } static void mptcp_stop_rtx_timer(struct sock *sk) -- cgit v1.2.3 From 51e398a3b8961b26a8c0a4ba9a777c5339791707 Mon Sep 17 00:00:00 2001 From: Li Xiasong Date: Fri, 15 May 2026 06:27:33 +0200 Subject: mptcp: pm: fix ADD_ADDR timer infinite retry on option space insufficient When TCP option space is insufficient (e.g., when sending ADD_ADDR with an IPv6 address and port while tcp_timestamps is enabled), the original code jumped to out_unlock without clearing the addr_signal flag. This caused mptcp_pm_add_timer to keep rescheduling indefinitely, not sending ADD_ADDR, preventing subsequent addresses in the endpoint list from being announced. Handle this case by clearing the ADD_ADDR signal and skipping the matching ADD_ADDR retransmission entry. The skip path cancels the matching timer (with id check) and advances PM state progression, preserving forward progress to subsequent PM work. This cancellation is inherently best-effort. A concurrent add_timer callback may already be running and may acquire pm.lock before the cancel path updates entry state. In that case, one final ADD_ADDR transmit attempt can still be executed. Once the cancel path sets entry->retrans_times to ADD_ADDR_RETRANS_MAX, the callback-side retrans_times check suppresses further ADD_ADDR retransmissions. Note that when an ADD_ADDR is being prepared, a pure-ACK is queued. On the output side, it means that it is fine to skip non-pure-ACK packets, when drop_other_suboptions is set: a pure-ACK will be processed soon after. Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") Cc: stable@vger.kernel.org Signed-off-by: Li Xiasong Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260515-net-mptcp-misc-fixes-7-1-rc4-v2-2-701e96419f2f@kernel.org Signed-off-by: Paolo Abeni --- net/mptcp/pm.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 46 insertions(+), 10 deletions(-) (limited to 'net') diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 3c152bf66cd5..3e770c7407e1 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -364,7 +364,13 @@ static void mptcp_pm_add_timer(struct timer_list *timer) spin_lock_bh(&msk->pm.lock); - if (!mptcp_pm_should_add_signal_addr(msk)) { + /* The cancel path (mptcp_pm_del_add_timer()) can race with this + * callback. Once cancel updates retrans_times to MAX, suppress further + * retransmissions here. If this callback acquires pm.lock first, one + * final transmit attempt is still possible. + */ + if (entry->retrans_times < ADD_ADDR_RETRANS_MAX && + !mptcp_pm_should_add_signal_addr(msk)) { pr_debug("retransmit ADD_ADDR id=%d\n", entry->addr.id); mptcp_pm_announce_addr(msk, &entry->addr, false); mptcp_pm_add_addr_send_ack(msk); @@ -414,8 +420,12 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk, /* Note: entry might have been removed by another thread. * We hold rcu_read_lock() to ensure it is not freed under us. */ - if (stop_timer) - sk_stop_timer_sync(sk, &entry->add_timer); + if (stop_timer) { + if (check_id) + sk_stop_timer(sk, &entry->add_timer); + else + sk_stop_timer_sync(sk, &entry->add_timer); + } rcu_read_unlock(); return entry; @@ -882,6 +892,7 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb, struct mptcp_addr_info *addr, bool *echo, bool *drop_other_suboptions) { + bool skip_add_addr = false; int ret = false; u8 add_addr; u8 family; @@ -903,24 +914,49 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb, } *echo = mptcp_pm_should_add_signal_echo(msk); - port = !!(*echo ? msk->pm.remote.port : msk->pm.local.port); - - family = *echo ? msk->pm.remote.family : msk->pm.local.family; - if (remaining < mptcp_add_addr_len(family, *echo, port)) - goto out_unlock; - if (*echo) { *addr = msk->pm.remote; add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_ECHO); + port = !!msk->pm.remote.port; + family = msk->pm.remote.family; } else { *addr = msk->pm.local; add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_SIGNAL); + port = !!msk->pm.local.port; + family = msk->pm.local.family; } - WRITE_ONCE(msk->pm.addr_signal, add_addr); + + if (remaining < mptcp_add_addr_len(family, *echo, port)) { + struct net *net = sock_net((struct sock *)msk); + + if (!*drop_other_suboptions) + goto out_unlock; + + if (*echo) { + MPTCP_INC_STATS(net, MPTCP_MIB_ECHOADDTXDROP); + } else { + skip_add_addr = true; + MPTCP_INC_STATS(net, MPTCP_MIB_ADDADDRTXDROP); + } + goto drop_signal_mark; + } + ret = true; +drop_signal_mark: + WRITE_ONCE(msk->pm.addr_signal, add_addr); + out_unlock: spin_unlock_bh(&msk->pm.lock); + + /* On pure-ACK option-space exhaustion, stop retrying this ADD_ADDR: + * clear the signal bit, cancel the matching retransmission timer, and + * let the PM state machine progress. + */ + if (skip_add_addr) { + mptcp_pm_del_add_timer(msk, addr, true); + mptcp_pm_subflow_established(msk); + } return ret; } -- cgit v1.2.3 From 0981f90e1a05773a4c29c6e720f5ea1e3c8f1876 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Fri, 15 May 2026 06:27:35 +0200 Subject: mptcp: reset rcv wnd on disconnect If the MPTCP socket fallback to TCP before the MP handshake completion, the IASN remain 0, and the rcv_wnd_sent field is not explicitly initialized, just incremented over time with the data transfer. At disconnect time such value is not cleared. If the next connection falls back to TCP before the MP handshake completion, the data transfer will keep incrementing the receive window end sequence starting from the last value used in the previous connection: the announced window will be unrelated from the actual receiver buffer size and likely too big. Address the issue zeroing the field at disconnect time. Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260515-net-mptcp-misc-fixes-7-1-rc4-v2-4-701e96419f2f@kernel.org Signed-off-by: Paolo Abeni --- net/mptcp/protocol.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net') diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 859df49e16dc..a72a6ad6ee8b 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3487,6 +3487,7 @@ static int mptcp_disconnect(struct sock *sk, int flags) /* for fallback's sake */ WRITE_ONCE(msk->ack_seq, 0); + atomic64_set(&msk->rcv_wnd_sent, 0); WRITE_ONCE(sk->sk_shutdown, 0); sk_error_report(sk); -- cgit v1.2.3 From 3a543ae0e2092d5c2085d5f21f7a7dbafdffea3c Mon Sep 17 00:00:00 2001 From: Gang Yan Date: Fri, 15 May 2026 06:27:36 +0200 Subject: mptcp: update window_clamp on subflows when SO_RCVBUF is set Add __mptcp_subflow_set_rcvbuf() helper to write the subflow sk_rcvbuf, but also to call the recently added tcp_set_rcvbuf() helper to update window_clamp. This is needed because the window clap is updated when scaling_ratio changes, in tcp_measure_rcv_mss(). Until scaling_ratio changes, the subflow is stuck with the old window clamp which may be based on a small initial buffer. Use this new helper in both mptcp_sol_socket_sync_intval() (setsockopt path) and sync_socket_options() (new subflow creation path). Note that this patch depends on commit b025461303d8 ("tcp: update window_clamp when SO_RCVBUF is set"): it fixes the issue on TCP side, but the same fix is needed on MPTCP side as well. Fixes: a2cbb1603943 ("tcp: Update window clamping condition") Cc: stable@vger.kernel.org Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/619 Signed-off-by: Gang Yan Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260515-net-mptcp-misc-fixes-7-1-rc4-v2-5-701e96419f2f@kernel.org Signed-off-by: Paolo Abeni --- net/mptcp/sockopt.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 1cf608e7357b..87b5796d0135 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -67,6 +67,12 @@ static int mptcp_get_int_option(struct mptcp_sock *msk, sockptr_t optval, return 0; } +static void __mptcp_subflow_set_rcvbuf(struct sock *ssk, int val) +{ + WRITE_ONCE(ssk->sk_rcvbuf, val); + tcp_set_rcvbuf(ssk, val); +} + static void mptcp_sol_socket_sync_intval(struct mptcp_sock *msk, int optname, int val) { struct mptcp_subflow_context *subflow; @@ -100,7 +106,7 @@ static void mptcp_sol_socket_sync_intval(struct mptcp_sock *msk, int optname, in case SO_RCVBUF: case SO_RCVBUFFORCE: ssk->sk_userlocks |= SOCK_RCVBUF_LOCK; - WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf); + __mptcp_subflow_set_rcvbuf(ssk, sk->sk_rcvbuf); break; case SO_MARK: if (READ_ONCE(ssk->sk_mark) != sk->sk_mark) { @@ -1560,7 +1566,7 @@ static void sync_socket_options(struct mptcp_sock *msk, struct sock *ssk) mptcp_subflow_ctx(ssk)->cached_sndbuf = sk->sk_sndbuf; } if (sk->sk_userlocks & SOCK_RCVBUF_LOCK) - WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf); + __mptcp_subflow_set_rcvbuf(ssk, sk->sk_rcvbuf); } if (sock_flag(sk, SOCK_LINGER)) { -- cgit v1.2.3 From 4df78ff02629c7729168f0696a7a2123c389818d Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Sun, 17 May 2026 15:11:21 +0300 Subject: bridge: mcast: Fix a possible use-after-free when removing a bridge port When per-VLAN multicast snooping is enabled, the bridge iterates over all the bridge ports, disables the per-port multicast context on each port and enables the per-{port, VLAN} multicast contexts instead. The reverse happens when per-VLAN multicast snooping is disabled. When global multicast snooping is enabled, the bridge iterates over all the bridge ports and enables the per-port multicast context on each port. The reverse happens when multicast snooping is disabled. The above scheme can result in a situation where both types of contexts (per-port and per-{port, VLAN}) are enabled on a single bridge port: # ip link add name br1 up type bridge mcast_snooping 1 mcast_querier 1 vlan_filtering 1 # ip link add name dummy1 up master br1 type dummy # ip link set dev br1 type bridge mcast_vlan_snooping 1 # ip link set dev br1 type bridge mcast_snooping 0 # ip link set dev br1 type bridge mcast_snooping 1 This is not intended and it is a problem since the commit cited below. Prior to this commit, when removing a bridge port, br_multicast_disable_port() would disable the per-port multicast context and the per-{port, VLAN} multicast contexts would get disabled when flushing VLANs. After this commit, br_multicast_disable_port() only disables the per-port multicast context if per-VLAN multicast snooping is disabled. If both types of contexts were enabled on the port when it was removed, the per-port multicast context would remain enabled when freeing the bridge port, leading to a use-after-free [1]. Fix by preventing the bridge from enabling / disabling the per-port multicast contexts when toggling global multicast snooping if per-VLAN multicast snooping is enabled. [1] ODEBUG: free active (active state 0) object: ffff88810f8bda78 object type: timer_list hint: br_ip6_multicast_port_query_expired (net/bridge/br_multicast.c:1927) WARNING: lib/debugobjects.c:629 at debug_print_object+0x1b1/0x3e0, CPU#5: swapper/5/0 [...] Call Trace: __debug_check_no_obj_freed (lib/debugobjects.c:1116) kfree (mm/slub.c:2620 mm/slub.c:6250 mm/slub.c:6565) kobject_cleanup (lib/kobject.c:689) rcu_do_batch (kernel/rcu/tree.c:2617) rcu_core (kernel/rcu/tree.c:2869) handle_softirqs (kernel/softirq.c:622) __irq_exit_rcu (kernel/softirq.c:656 kernel/softirq.c:496 kernel/softirq.c:735) irq_exit_rcu (kernel/softirq.c:752) sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1061 (discriminator 47) arch/x86/kernel/apic/apic.c:1061 (discriminator 47)) Fixes: 4b30ae9adb04 ("net: bridge: mcast: re-implement br_multicast_{enable, disable}_port functions") Reported-by: syzbot+ae231e0552fa77b26ea1@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/87qznowlfs.ffs@tglx/ Reported-by: Thomas Gleixner Acked-by: Nikolay Aleksandrov Signed-off-by: Ido Schimmel Link: https://patch.msgid.link/20260517121122.188333-2-idosch@nvidia.com Signed-off-by: Jakub Kicinski --- net/bridge/br_multicast.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) (limited to 'net') diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 881d866d687a..2eef4f3345cd 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -4640,10 +4640,24 @@ static void br_multicast_start_querier(struct net_bridge_mcast *brmctx, rcu_read_unlock(); } -static void br_multicast_del_grps(struct net_bridge *br) +static void br_multicast_enable_all_ports(struct net_bridge *br) { struct net_bridge_port *port; + if (br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED)) + return; + + list_for_each_entry(port, &br->port_list, list) + __br_multicast_enable_port_ctx(&port->multicast_ctx); +} + +static void br_multicast_disable_all_ports(struct net_bridge *br) +{ + struct net_bridge_port *port; + + if (br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED)) + return; + list_for_each_entry(port, &br->port_list, list) __br_multicast_disable_port_ctx(&port->multicast_ctx); } @@ -4651,7 +4665,6 @@ static void br_multicast_del_grps(struct net_bridge *br) int br_multicast_toggle(struct net_bridge *br, unsigned long val, struct netlink_ext_ack *extack) { - struct net_bridge_port *port; bool change_snoopers = false; int err = 0; @@ -4668,7 +4681,7 @@ int br_multicast_toggle(struct net_bridge *br, unsigned long val, br_opt_toggle(br, BROPT_MULTICAST_ENABLED, !!val); if (!br_opt_get(br, BROPT_MULTICAST_ENABLED)) { change_snoopers = true; - br_multicast_del_grps(br); + br_multicast_disable_all_ports(br); goto unlock; } @@ -4676,8 +4689,7 @@ int br_multicast_toggle(struct net_bridge *br, unsigned long val, goto unlock; br_multicast_open(br); - list_for_each_entry(port, &br->port_list, list) - __br_multicast_enable_port_ctx(&port->multicast_ctx); + br_multicast_enable_all_ports(br); change_snoopers = true; -- cgit v1.2.3 From d4ea0dfd75011b78cebf3808f98ac4c4f51a6fb9 Mon Sep 17 00:00:00 2001 From: Justin Iurman Date: Sun, 17 May 2026 20:30:59 +0200 Subject: ipv6: ioam: add NULL check for idev in ipv6_hop_ioam() Reported by Sashiko: The function ipv6_hop_ioam() accesses __in6_dev_get(skb->dev)->cnf.ioam6_enabled without validating the returned idev pointer. Because addrconf_ifdown() can concurrently clear dev->ip6_ptr via RCU, __in6_dev_get() can return NULL during interface teardown, which could cause a NULL pointer dereference when processing an IOAM Hop-by-Hop option. Let's add a check and use SKB_DROP_REASON_IPV6DISABLED accordingly. Fixes: 9ee11f0fff20 ("ipv6: ioam: Data plane support for Pre-allocated Trace") Cc: stable@vger.kernel.org Signed-off-by: Justin Iurman Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260517183059.29140-1-justin.iurman@gmail.com Signed-off-by: Jakub Kicinski --- net/ipv6/exthdrs.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 03cbce842c1a..47c5502a34a2 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -910,16 +910,27 @@ static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) { + enum skb_drop_reason drop_reason; struct ioam6_trace_hdr *trace; struct ioam6_namespace *ns; + struct inet6_dev *idev; struct ioam6_hdr *hdr; + drop_reason = SKB_DROP_REASON_IP_INHDR; + /* Bad alignment (must be 4n-aligned) */ if (optoff & 3) goto drop; + /* Does the device still have IPv6 configuration? */ + idev = __in6_dev_get(skb->dev); + if (!idev) { + drop_reason = SKB_DROP_REASON_IPV6DISABLED; + goto drop; + } + /* Ignore if IOAM is not enabled on ingress */ - if (!READ_ONCE(__in6_dev_get(skb->dev)->cnf.ioam6_enabled)) + if (!READ_ONCE(idev->cnf.ioam6_enabled)) goto ignore; /* Truncated Option header */ @@ -972,7 +983,7 @@ ignore: return true; drop: - kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); + kfree_skb_reason(skb, drop_reason); return false; } -- cgit v1.2.3 From be309f8eae8b474a4a617eaae01324da996fc719 Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Mon, 18 May 2026 18:51:30 +0200 Subject: af_unix: Fix UAF read of tail->len in unix_stream_data_wait() unix_stream_data_wait() does skb_peek_tail(&sk->sk_receive_queue) without holding any lock that prevents SKBs on that queue from being dequeued and freed. This has been the case since commit 79f632c71bea ("unix/stream: fix peeking with an offset larger than data in queue"). The first consequence of this is that the pointer comparison `tail != last` can be false even if `last` semantically refers to an already-freed SKB while `tail` is a new SKB allocated at the same address; which can cause unix_stream_data_wait() to wrongly keep blocking after new data has arrived, but only in a weird scenario where a peeking recv() and a normal recv() on the same socket are racing, which is probably not a real problem. But since commit 2b514574f7e8 ("net: af_unix: implement splice for stream af_unix sockets"), `tail` is actually dereferenced, which can cause UAF in the following race scenario (where test_setup() runs single-threaded, and afterwards, test_thread1() and test_thread2() run concurrently in two threads: ``` static int socks[2]; void test_setup(void) { socketpair(AF_UNIX, SOCK_STREAM, 0, socks); send(socks[1], "A", 1, 0); int peekoff = 1; setsockopt(socks[0], SOL_SOCKET, SO_PEEK_OFF, &peekoff, sizeof(peekoff)); } void test_thread1(void) { char dummy; recv(socks[0], &dummy, 1, MSG_PEEK); } void test_thread2(void) { char dummy; recv(socks[0], &dummy, 1, 0); shutdown(socks[1], SHUT_WR); } ``` when racing like this: ``` thread1 thread2 unix_stream_read_generic mutex_lock(&u->iolock) skb_peek(&sk->sk_receive_queue) skb_peek_next(skb, &sk->sk_receive_queue) mutex_unlock(&u->iolock) unix_stream_read_generic unix_state_lock(sk) skb_peek(&sk->sk_receive_queue) unix_state_unlock(sk) unix_stream_data_wait unix_state_lock(sk) tail = skb_peek_tail(&sk->sk_receive_queue) spin_lock(&sk->sk_receive_queue.lock) __skb_unlink(skb, &sk->sk_receive_queue) spin_unlock(&sk->sk_receive_queue.lock) consume_skb(skb) [frees the SKB] `tail != last`: false `tail`: true `tail->len != last_len` ***UAF*** ``` Fix the UAF by removing the read of tail->len; checking tail->len would only make sense if SKBs in the receive queue of a UNIX socket could grow, which can no longer happen. Kuniyuki explained: > When commit 869e7c62486e ("net: af_unix: implement stream sendpage > support") added sendpage() support, data could be appended to the last > skb in the receiver's queue. > > That's why we needed to check if the length of the last skb was changed > while waiting for new data in unix_stream_data_wait(). > > However, commit a0dbf5f818f9 ("af_unix: Support MSG_SPLICE_PAGES") and > commit 57d44a354a43 ("unix: Convert unix_stream_sendpage() to use > MSG_SPLICE_PAGES") refactored sendmsg(), and now data is always added > to a new skb. That means this fix is not suitable for kernels before 6.5. Fixes: 2b514574f7e8 ("net: af_unix: implement splice for stream af_unix sockets") Cc: stable@vger.kernel.org # 6.5.x Signed-off-by: Jann Horn Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260518-b4-unix-recv-wait-hotfix-v2-1-83e29ce8ad31@google.com Signed-off-by: Jakub Kicinski --- net/unix/af_unix.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) (limited to 'net') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 1cbf36ea043b..dc71ed79be4a 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2711,8 +2711,7 @@ static int unix_read_skb(struct sock *sk, skb_read_actor_t recv_actor) * Sleep until more data has arrived. But check for races.. */ static long unix_stream_data_wait(struct sock *sk, long timeo, - struct sk_buff *last, unsigned int last_len, - bool freezable) + struct sk_buff *last, bool freezable) { unsigned int state = TASK_INTERRUPTIBLE | freezable * TASK_FREEZABLE; struct sk_buff *tail; @@ -2725,7 +2724,6 @@ static long unix_stream_data_wait(struct sock *sk, long timeo, tail = skb_peek_tail(&sk->sk_receive_queue); if (tail != last || - (tail && tail->len != last_len) || sk->sk_err || (sk->sk_shutdown & RCV_SHUTDOWN) || signal_pending(current) || @@ -2921,7 +2919,6 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state, int flags = state->flags; bool check_creds = false; struct scm_cookie scm; - unsigned int last_len; struct unix_sock *u; int copied = 0; int err = 0; @@ -2967,7 +2964,6 @@ redo: goto unlock; } last = skb = skb_peek(&sk->sk_receive_queue); - last_len = last ? last->len : 0; again: #if IS_ENABLED(CONFIG_AF_UNIX_OOB) @@ -3001,8 +2997,7 @@ again: mutex_unlock(&u->iolock); - timeo = unix_stream_data_wait(sk, timeo, last, - last_len, freezable); + timeo = unix_stream_data_wait(sk, timeo, last, freezable); if (signal_pending(current)) { err = sock_intr_errno(timeo); @@ -3019,7 +3014,6 @@ unlock: while (skip >= unix_skb_len(skb)) { skip -= unix_skb_len(skb); last = skb; - last_len = skb->len; skb = skb_peek_next(skb, &sk->sk_receive_queue); if (!skb) goto again; @@ -3094,7 +3088,6 @@ unlock: skip = 0; last = skb; - last_len = skb->len; unix_state_lock(sk); skb = skb_peek_next(skb, &sk->sk_receive_queue); if (skb) -- cgit v1.2.3 From f718506edd2d9c6a308ded9d13c632bf7b7d5a2c Mon Sep 17 00:00:00 2001 From: Alexandru Hossu Date: Fri, 15 May 2026 12:29:08 +0200 Subject: wifi: mac80211: bounds-check link_id in ieee80211_ml_epcs IEEE80211_MLE_STA_EPCS_CONTROL_LINK_ID is 0x000f, so link_id extracted from a PRIO_ACCESS ML element PER_STA_PROFILE subelement can be 0..15. sdata->link[] has IEEE80211_MLD_MAX_NUM_LINKS (15) entries (indices 0..14), making index 15 out-of-bounds. A connected WiFi 7 AP can trigger this by sending an EPCS Enable Response action frame with a PER_STA_PROFILE subelement where link_id = 15. The unsolicited-notification path (dialog_token = 0) is reachable any time EPCS is already enabled, without any prior client request. sdata->link[15] reads into the first word of sdata->activate_links_work (a wiphy_work whose embedded list_head is non-NULL after INIT_LIST_HEAD), so the NULL check on the result does not catch the invalid access. The garbage pointer is then passed to ieee80211_sta_wmm_params(), which dereferences link->sdata and crashes the kernel. The same class of bug was fixed for ieee80211_ml_reconfiguration() by commit 162d331d833d ("wifi: mac80211: bounds-check link_id in ieee80211_ml_reconfiguration"). Fixes: de86c5f60839 ("wifi: mac80211: Add support for EPCS configuration") Signed-off-by: Alexandru Hossu Link: https://patch.msgid.link/20260515102908.1653088-1-hossu.alexandru@gmail.com Signed-off-by: Johannes Berg --- net/mac80211/mlme.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net') diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 0a0f27836d57..ca1d29daf019 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -11232,6 +11232,9 @@ static void ieee80211_ml_epcs(struct ieee80211_sub_if_data *sdata, control = get_unaligned_le16(pos); link_id = control & IEEE80211_MLE_STA_EPCS_CONTROL_LINK_ID; + if (link_id >= IEEE80211_MLD_MAX_NUM_LINKS) + continue; + link = sdata_dereference(sdata->link[link_id], sdata); if (!link) continue; -- cgit v1.2.3 From e1e83feb8eae82cc9cc676db4c70f52fedc4735d Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Wed, 13 May 2026 17:06:27 +0300 Subject: wifi: mac80211: don't override max_amsdu_subframes In client mode, the extended capabilities are handled by the kernel looking at the association frame. When the supplicant installs the keys it calls sta_apply_parameters and it doesn't include the extended capabilities since those can't change after association. As a result, we overrode the max_amsdu_subframes that we set after association. Check that the ext_capa coming from the user space is valid before looking at it. If the ext_capa is NULL, it really means that the extended capabilities are not changed (as opposed to cleared). The default value for max_amsdu_subframes is 0, which means there is no limit. This value is valid and in case the association response frame does not have extended capabilities, this is the value we should use. Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221079 Signed-off-by: Emmanuel Grumbach Reviewed-by: Johannes Berg Signed-off-by: Miri Korenblit Link: https://patch.msgid.link/20260513170623.828dbb58c782.Ifd2bfc190c26140e919127adb02ffddd7b551499@changeid Signed-off-by: Johannes Berg --- net/mac80211/cfg.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 7b77d57c9f96..f9ee9947a94d 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -2344,8 +2344,9 @@ static int sta_apply_parameters(struct ieee80211_local *local, sta->sta.max_sp = params->max_sp; } - ieee80211_sta_set_max_amsdu_subframes(sta, params->ext_capab, - params->ext_capab_len); + if (params->ext_capab) + ieee80211_sta_set_max_amsdu_subframes(sta, params->ext_capab, + params->ext_capab_len); /* * cfg80211 validates this (1-2007) and allows setting the AID -- cgit v1.2.3 From a74e893f30db64cdce0fc7a96d3baa417bcd55f5 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 8 May 2026 09:10:31 +0200 Subject: wifi: mac80211: fix MLE defragmentation If either reconf or EPCS multi-link element (MLE) is contained in a non-transmitted profile, the defragmentation routine is called with a pointer to the defragmented copy, but the original elements. This is incorrect for two reasons: - if the original defragmentation was needed, it will not find the correct data - if the original frame is at a higher address, the parsing will potentially overrun the heap data (though given the layout of the buffers, only into the new defragmentation buffer, and then it has to stop and fail once that's filled with copied data. Fix it by tracking the container along with the pointer and in doing so also unify the two almost identical defragmentation routines. Fixes: 4d70e9c5488d ("wifi: mac80211: defragment reconfiguration MLE when parsing") Reviewed-by: Miriam Rachel Korenblit Reviewed-by: Ilan Peer Link: https://patch.msgid.link/20260508091031.8a6c34613178.I4de16ebbce2d27f2f8f98fc49949c7a376c2fe8d@changeid Signed-off-by: Johannes Berg --- net/mac80211/parse.c | 71 +++++++++++++++++++++++----------------------------- 1 file changed, 31 insertions(+), 40 deletions(-) (limited to 'net') diff --git a/net/mac80211/parse.c b/net/mac80211/parse.c index 2b3632c6008a..666cdd5fd0ea 100644 --- a/net/mac80211/parse.c +++ b/net/mac80211/parse.c @@ -34,6 +34,13 @@ #include "led.h" #include "wep.h" +struct ieee80211_elem_defrag { + const struct element *elem; + /* container start/len */ + const u8 *start; + size_t len; +}; + struct ieee80211_elems_parse { /* must be first for kfree to work */ struct ieee802_11_elems elems; @@ -41,11 +48,7 @@ struct ieee80211_elems_parse { /* The basic Multi-Link element in the original elements */ const struct element *ml_basic_elem; - /* The reconfiguration Multi-Link element in the original elements */ - const struct element *ml_reconf_elem; - - /* The EPCS Multi-Link element in the original elements */ - const struct element *ml_epcs_elem; + struct ieee80211_elem_defrag ml_reconf, ml_epcs; bool multi_link_inner; bool skip_vendor; @@ -162,10 +165,14 @@ ieee80211_parse_extension_element(u32 *crc, } break; case IEEE80211_ML_CONTROL_TYPE_RECONF: - elems_parse->ml_reconf_elem = elem; + elems_parse->ml_reconf.elem = elem; + elems_parse->ml_reconf.start = params->start; + elems_parse->ml_reconf.len = params->len; break; case IEEE80211_ML_CONTROL_TYPE_PRIO_ACCESS: - elems_parse->ml_epcs_elem = elem; + elems_parse->ml_epcs.elem = elem; + elems_parse->ml_epcs.start = params->start; + elems_parse->ml_epcs.len = params->len; break; default: break; @@ -990,46 +997,27 @@ ieee80211_prep_mle_link_parse(struct ieee80211_elems_parse *elems_parse, sub->start, sub->len); } -static void -ieee80211_mle_defrag_reconf(struct ieee80211_elems_parse *elems_parse) -{ - struct ieee802_11_elems *elems = &elems_parse->elems; - ssize_t ml_len; - - ml_len = cfg80211_defragment_element(elems_parse->ml_reconf_elem, - elems->ie_start, - elems->total_len, - elems_parse->scratch_pos, - elems_parse->scratch + - elems_parse->scratch_len - - elems_parse->scratch_pos, - WLAN_EID_FRAGMENT); - if (ml_len < 0) - return; - elems->ml_reconf = (void *)elems_parse->scratch_pos; - elems->ml_reconf_len = ml_len; - elems_parse->scratch_pos += ml_len; -} - -static void -ieee80211_mle_defrag_epcs(struct ieee80211_elems_parse *elems_parse) +static const void * +ieee80211_mle_defrag(struct ieee80211_elems_parse *elems_parse, + struct ieee80211_elem_defrag *defrag, + size_t *out_len) { - struct ieee802_11_elems *elems = &elems_parse->elems; + const void *ret; ssize_t ml_len; - ml_len = cfg80211_defragment_element(elems_parse->ml_epcs_elem, - elems->ie_start, - elems->total_len, + ml_len = cfg80211_defragment_element(defrag->elem, + defrag->start, defrag->len, elems_parse->scratch_pos, elems_parse->scratch + elems_parse->scratch_len - elems_parse->scratch_pos, WLAN_EID_FRAGMENT); if (ml_len < 0) - return; - elems->ml_epcs = (void *)elems_parse->scratch_pos; - elems->ml_epcs_len = ml_len; + return NULL; + ret = elems_parse->scratch_pos; + *out_len = ml_len; elems_parse->scratch_pos += ml_len; + return ret; } struct ieee802_11_elems * @@ -1109,9 +1097,12 @@ ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params) _ieee802_11_parse_elems_full(&sub, elems_parse, NULL); } - ieee80211_mle_defrag_reconf(elems_parse); - - ieee80211_mle_defrag_epcs(elems_parse); + elems->ml_reconf = ieee80211_mle_defrag(elems_parse, + &elems_parse->ml_reconf, + &elems->ml_reconf_len); + elems->ml_epcs = ieee80211_mle_defrag(elems_parse, + &elems_parse->ml_epcs, + &elems->ml_epcs_len); if (elems->tim && !elems->parse_error) { const struct ieee80211_tim_ie *tim_ie = elems->tim; -- cgit v1.2.3 From fe2d61a5d2849ee75dd4deeb2fe35f78d80721f8 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 8 May 2026 09:10:32 +0200 Subject: wifi: mac80211: fix multi-link element inheritance When parsing a beacon, mac80211 erroneously inherits any reconfiguration or EPCS multi-link elements from the outer elements into the multi-BSSID profile that's requested, if connected to a non-transmitted BSS, unless that profile has a non-inheritance element. This also happens if parsing a multi-BSSID profile that doesn't have a non-inheritance element. Fix this by having an empty non-inheritance element so cfg80211_is_element_inherited() is invoked in these cases and causes the parser to skip the elements that should never be inherited. Fixes: cf36cdef10e2 ("wifi: mac80211: Add support for parsing Reconfiguration Multi Link element") Fixes: 24711d60f849 ("wifi: mac80211: Support parsing EPCS ML element") Reviewed-by: Ilan Peer Reviewed-by: Benjamin Berg Link: https://patch.msgid.link/20260508091032.92184c0a3f08.I3c43b0b63d2cef8a4ddddaef1c2faaeb1de711ad@changeid Signed-off-by: Johannes Berg --- net/mac80211/parse.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/mac80211/parse.c b/net/mac80211/parse.c index 666cdd5fd0ea..77894d997113 100644 --- a/net/mac80211/parse.c +++ b/net/mac80211/parse.c @@ -34,6 +34,15 @@ #include "led.h" #include "wep.h" +static const u8 empty_non_inheritance[] = { + WLAN_EID_EXTENSION, 1, WLAN_EID_EXT_NON_INHERITANCE, + /* + * cfg80211_is_element_inherited() hardcodes elements that + * cannot be inherited, so we just need an empty one to be + * calling it at all. + */ +}; + struct ieee80211_elem_defrag { const struct element *elem; /* container start/len */ @@ -923,7 +932,7 @@ ieee80211_prep_mle_link_parse(struct ieee80211_elems_parse *elems_parse, { struct ieee802_11_elems *elems = &elems_parse->elems; struct ieee80211_mle_per_sta_profile *prof; - const struct element *tmp; + const struct element *tmp, *ret; ssize_t ml_len; const u8 *end; @@ -993,8 +1002,17 @@ ieee80211_prep_mle_link_parse(struct ieee80211_elems_parse *elems_parse, sub->from_ap = params->from_ap; sub->link_id = -1; - return cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE, - sub->start, sub->len); + ret = cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE, + sub->start, sub->len); + if (ret) + return ret; + + /* + * Since we know we want and found a profile, apply an empty + * non-inheritance if the profile didn't have one, so that any + * element that shouldn't be inherited by spec isn't. + */ + return (const void *)empty_non_inheritance; } static const void * @@ -1030,6 +1048,7 @@ ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params) size_t scratch_len = 3 * params->len; bool multi_link_inner = false; + BUILD_BUG_ON(sizeof(empty_non_inheritance) != empty_non_inheritance[1] + 2); BUILD_BUG_ON(offsetof(typeof(*elems_parse), elems) != 0); /* cannot parse for both a specific link and non-transmitted BSS */ @@ -1077,6 +1096,17 @@ ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params) non_inherit = cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE, sub.start, nontx_len); + /* + * If it's a non-transmitted BSS, we shouldn't pick + * any elements in the outer parsing that shouldn't + * be inherited. If the profile has a non-inheritance + * element this automatically happens, but if not then + * provide an empty one so that the hard-coded elements + * in cfg80211_is_element_inherited() are ignored, but + * it must be called. + */ + if (params->bss->transmitted_bss && !non_inherit) + non_inherit = (const void *)empty_non_inheritance; } else { /* must always parse to get elems_parse->ml_basic_elem */ non_inherit = ieee80211_prep_mle_link_parse(elems_parse, params, -- cgit v1.2.3 From d71c841be5d9e586ee7f36c0dc8ed4db0d9a1349 Mon Sep 17 00:00:00 2001 From: Zhao Li Date: Sat, 9 May 2026 12:34:28 +0800 Subject: wifi: mac80211: capture fast-RX rate before mesh reuses skb->cb ieee80211_invoke_fast_rx() reads RX status through IEEE80211_SKB_RXCB(skb), which aliases the same skb->cb storage that ieee80211_rx_mesh_data() reuses as IEEE80211_TX_INFO. In the unicast forward path, mesh_data does: info = IEEE80211_SKB_CB(fwd_skb); memset(info, 0, sizeof(*info)); on the same skb the caller still names via rx->skb, then either queues the skb for TX (success) or kfree_skb()'s it (no-route) before returning RX_QUEUED. The caller's RX_QUEUED arm then calls sta_stats_encode_rate(status) on memory that is either zeroed (success path) or freed (no-route path). The latter is KASAN slab-use-after-free in ieee80211_prepare_and_rx_handle. Fix by encoding the rate from status before invoking ieee80211_rx_mesh_data(), so the RX_QUEUED arm consumes a value captured while status was still backed by valid memory. Fixes: 3468e1e0c639 ("wifi: mac80211: add mesh fast-rx support") Cc: stable@vger.kernel.org Signed-off-by: Zhao Li Link: https://patch.msgid.link/20260509043427.60322-2-enderaoelyther@gmail.com Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index d18e962126ce..3fb40449c6c5 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -4984,6 +4984,7 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx, u8 sa[ETH_ALEN]; } addrs __aligned(2); struct ieee80211_sta_rx_stats *stats; + u32 encoded_rate; /* for parallel-rx, we need to have DUP_VALIDATED, otherwise we write * to a common data structure; drivers can implement that per queue @@ -5091,11 +5092,14 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx, /* push the addresses in front */ memcpy(skb_push(skb, sizeof(addrs)), &addrs, sizeof(addrs)); + /* capture before mesh forward may memset or free skb->cb */ + encoded_rate = sta_stats_encode_rate(status); + res = ieee80211_rx_mesh_data(rx->sdata, rx->sta, rx->skb); switch (res) { case RX_QUEUED: stats->last_rx = jiffies; - stats->last_rate = sta_stats_encode_rate(status); + stats->last_rate = encoded_rate; return true; case RX_CONTINUE: break; -- cgit v1.2.3 From a6e6ccd5bd07155c2add6c74ce1a5e68ad3b95ea Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Fri, 15 May 2026 11:17:18 -0400 Subject: wifi: mac80211: consume only present negotiated TTLM maps ieee80211_tid_to_link_map_size_ok() validates negotiated TTLM elements against the number of link-map entries indicated by link_map_presence. ieee80211_parse_neg_ttlm() must consume the same layout. The parser advanced its cursor for every TID, including TIDs whose presence bit is clear and therefore have no map bytes in the element. A sparse map can then make a later present TID read past the validated element. The bad bytes land in neg_ttlm->{up,down}link[tid] but are gated by valid_links before being applied to driver state, so a peer cannot turn the read into a policy change. Under KUnit + KASAN with an exact-sized element allocation the OOB read is reported as a slab-out-of-bounds; whether the same trigger fires under the production RX path depends on surrounding allocator state. Advance the cursor only when the current TID has a map present. Fixes: 8f500fbc6c65 ("wifi: mac80211: process and save negotiated TID to Link mapping request") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/20260515151719.1317659-2-michael.bommarito@gmail.com Signed-off-by: Johannes Berg --- net/mac80211/mlme.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index ca1d29daf019..b98ddfa3003e 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -8164,6 +8164,7 @@ ieee80211_parse_neg_ttlm(struct ieee80211_sub_if_data *sdata, "No active links for TID %d", tid); return -EINVAL; } + pos += map_size; } else { map = 0; } @@ -8182,7 +8183,6 @@ ieee80211_parse_neg_ttlm(struct ieee80211_sub_if_data *sdata, default: return -EINVAL; } - pos += map_size; } return 0; } -- cgit v1.2.3 From dc14686f27df6454b13b16ad1c9203ab3e9b0375 Mon Sep 17 00:00:00 2001 From: Kartik Nair Date: Mon, 11 May 2026 01:54:37 +0530 Subject: wifi: cfg80211: wext: validate chandef in monitor mode cfg80211_wext_siwfreq() constructs a channel definition for monitor mode but passes it to cfg80211_set_monitor_channel() without first validating it with cfg80211_chandef_valid(). This causes a WARN_ON in cfg80211_chandef_dfs_required() when it receives an invalid chandef. Add the missing cfg80211_chandef_valid() check before calling cfg80211_set_monitor_channel() to return -EINVAL early on invalid channel definitions, consistent with how other callers handle this. Reported-by: syzbot+02a1a03b8622d3c7d1c9@syzkaller.appspotmail.com Signed-off-by: Kartik Nair Link: https://patch.msgid.link/20260510202437.7857-1-contact.kartikn@gmail.com [clarify subject] Signed-off-by: Johannes Berg --- net/wireless/wext-compat.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net') diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c index 22d9d9bae8f5..63d145b524c9 100644 --- a/net/wireless/wext-compat.c +++ b/net/wireless/wext-compat.c @@ -789,6 +789,8 @@ static int cfg80211_wext_siwfreq(struct net_device *dev, chandef.chan = ieee80211_get_channel(&rdev->wiphy, freq); if (!chandef.chan) return -EINVAL; + if (!cfg80211_chandef_valid(&chandef)) + return -EINVAL; return cfg80211_set_monitor_channel(rdev, dev, &chandef); case NL80211_IFTYPE_MESH_POINT: freq = cfg80211_wext_freq(wextfreq); -- cgit v1.2.3 From 59e932ded949fa6f0340bf7c6d7818f962fa4fd2 Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Tue, 12 May 2026 22:15:39 +0200 Subject: Bluetooth: bnep: Fix UAF read of dev->name bnep_add_connection() needs to keep holding the bnep_session_sem while reading dev->name (just like bnep_get_connlist() does); otherwise the bnep_session() thread can concurrently free the net_device, which can for example be triggered by a concurrent bnep_del_connection(). (This UAF is fairly uninteresting from a security perspective; calling bnep_add_connection() requires passing a capable(CAP_NET_ADMIN) check. It also requires completely tearing down a netdev during a fairly tight race window.) Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jann Horn Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/bnep/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/bluetooth/bnep/core.c b/net/bluetooth/bnep/core.c index 853c8d7644b5..0de5df690bd0 100644 --- a/net/bluetooth/bnep/core.c +++ b/net/bluetooth/bnep/core.c @@ -645,8 +645,8 @@ int bnep_add_connection(struct bnep_connadd_req *req, struct socket *sock) goto failed; } - up_write(&bnep_session_sem); strcpy(req->device, dev->name); + up_write(&bnep_session_sem); return 0; failed: -- cgit v1.2.3 From 23d528d817a485fe9800a66c9411bd9e3d8a6f63 Mon Sep 17 00:00:00 2001 From: Luiz Augusto von Dentz Date: Thu, 14 May 2026 09:42:24 -0400 Subject: Bluetooth: hci_sync: Fix not setting mask for HCI_EVT_LE_ALL_REMOTE_FEATURES_COMPLETE This fixes not setting the bit for HCI_EVT_LE_ALL_REMOTE_FEATURES_COMPLETE when extended features bit is set otherwise the controller may not generate HCI_EVT_LE_ALL_REMOTE_FEATURES_COMPLETE causing hci_le_read_all_remote_features_sync to timeout waiting for it. Also remove dead code. Fixes: a106e50be74b ("Bluetooth: HCI: Add support for LL Extended Feature Set") Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/hci_sync.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index fd3aacdea512..aff8562a8690 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -4438,6 +4438,9 @@ static int hci_le_set_event_mask_sync(struct hci_dev *hdev) events[4] |= 0x02; /* LE BIG Info Advertising Report */ } + if (ll_ext_feature_capable(hdev)) + events[5] |= BIT(2); + if (le_cs_capable(hdev)) { /* Channel Sounding events */ events[5] |= 0x08; /* LE CS Read Remote Supported Cap Complete event */ @@ -7413,9 +7416,6 @@ static int hci_le_read_all_remote_features_sync(struct hci_dev *hdev, sizeof(cp), &cp, HCI_EVT_LE_ALL_REMOTE_FEATURES_COMPLETE, HCI_CMD_TIMEOUT, NULL); - - return __hci_cmd_sync_status(hdev, HCI_OP_LE_READ_ALL_REMOTE_FEATURES, - sizeof(cp), &cp, HCI_CMD_TIMEOUT); } static int hci_le_read_remote_features_sync(struct hci_dev *hdev, void *data) -- cgit v1.2.3 From 84c24fb151fc1179355296d7ff29129ac7c42129 Mon Sep 17 00:00:00 2001 From: David Carlier Date: Fri, 15 May 2026 07:25:25 +0100 Subject: Bluetooth: ISO: drop ISO_END frames received without prior ISO_START ISO data PDUs carry a packet-boundary flag indicating START, CONT, END or SINGLE. The ISO_CONT branch of iso_recv() guards against a missing ISO_START by checking conn->rx_len before touching conn->rx_skb, but ISO_END does not. If a peer sends an ISO_END as the first packet on a fresh ISO connection, conn->rx_skb is still NULL and conn->rx_len is zero, so skb_put(conn->rx_skb, ...) dereferences NULL and oopses. For BIS, where receivers sync to a broadcaster without pairing, any broadcaster on the air can trigger this. Mirror the ISO_CONT check at the top of ISO_END so a stray end fragment is logged and dropped instead of crashing the host. Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: David Carlier Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/iso.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'net') diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c index 7cb2864fe872..b971281f0a2b 100644 --- a/net/bluetooth/iso.c +++ b/net/bluetooth/iso.c @@ -2593,6 +2593,11 @@ int iso_recv(struct hci_dev *hdev, u16 handle, struct sk_buff *skb, u16 flags) break; case ISO_END: + if (!conn->rx_len) { + BT_ERR("Unexpected end frame (len %d)", skb->len); + goto drop; + } + skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len), skb->len); conn->rx_len -= skb->len; -- cgit v1.2.3 From d3f7d17960ed50df3a6709c5158caff989c8c905 Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Fri, 15 May 2026 10:38:19 -0400 Subject: Bluetooth: MGMT: validate Add Extended Advertising Data length MGMT_OP_ADD_EXT_ADV_DATA is registered as a variable-length command, with MGMT_ADD_EXT_ADV_DATA_SIZE as the fixed header size. The handler then uses cp->adv_data_len and cp->scan_rsp_len to validate and copy cp->data, but it never checks that those bytes are part of the mgmt command payload. A short command can therefore make add_ext_adv_data() pass an out-of-bounds pointer into tlv_data_is_valid(). If the bytes beyond the command buffer are addressable, they can also be copied into the advertising instance as scan response data, where the caller can read them back via MGMT_OP_GET_ADV_INSTANCE. The trigger requires CAP_NET_ADMIN in the initial user namespace; KASAN reports an 8-byte slab-out-of-bounds read. Reject commands whose length does not match the fixed header plus both advertising data lengths before parsing cp->data. Fixes: 12410572833a ("Bluetooth: Break add adv into two mgmt commands") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/mgmt.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'net') diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index b05bb380e5f8..de5bd6b637b2 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -9110,9 +9110,15 @@ static int add_ext_adv_data(struct sock *sk, struct hci_dev *hdev, void *data, struct adv_info *adv_instance; int err = 0; struct mgmt_pending_cmd *cmd; + u16 expected_len; BT_DBG("%s", hdev->name); + expected_len = struct_size(cp, data, cp->adv_data_len + cp->scan_rsp_len); + if (expected_len != data_len) + return mgmt_cmd_status(sk, hdev->id, MGMT_OP_ADD_EXT_ADV_DATA, + MGMT_STATUS_INVALID_PARAMS); + hci_dev_lock(hdev); adv_instance = hci_find_adv_instance(hdev, cp->instance); -- cgit v1.2.3 From ab1513597c6cf17cd1ad2a21e3b045421b48e022 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Safa=20Karaku=C5=9F?= Date: Sat, 16 May 2026 21:15:04 +0300 Subject: Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit bt_accept_dequeue() unlinks a not-yet-accepted child from the parent accept queue and release_sock()s it before returning, so the returned sk has no caller reference and is unlocked. l2cap_sock_cleanup_listen() walks these children on listening-socket close. A concurrent HCI disconnect drives hci_rx_work -> l2cap_conn_del() which runs l2cap_chan_del() + l2cap_sock_kill() and frees the child sk and its l2cap_chan; cleanup_listen() then uses both: BUG: KASAN: slab-use-after-free in l2cap_sock_kill l2cap_sock_kill / l2cap_sock_cleanup_listen / __x64_sys_close Freed by: l2cap_conn_del -> l2cap_sock_close_cb -> l2cap_sock_kill This is distinct from the two fixes already in this area: commit e83f5e24da741 ("Bluetooth: serialize accept_q access") serialises the accept_q list/poll and takes temporary refs inside bt_accept_dequeue(), and CVE-2025-39860 serialises the userspace close()/accept() race by calling cleanup_listen() under lock_sock() in l2cap_sock_release(). Neither covers l2cap_conn_del() running from hci_rx_work, so this UAF still reproduces on current bluetooth/master. Take the reference at the source: bt_accept_dequeue() does sock_hold() while sk is still locked, before release_sock(); callers sock_put(). cleanup_listen() pins the chan with l2cap_chan_hold_unless_zero() under a brief child sk lock (serialising vs l2cap_sock_teardown_cb()), drops it before l2cap_chan_lock(), and skips a duplicate l2cap_sock_kill() on SOCK_DEAD. conn->lock is not taken here: cleanup_listen() runs under the parent sk lock and that would invert conn->lock -> chan->lock -> sk_lock (lockdep). KASAN/SMP: an unprivileged listen/close vs HCI-disconnect race produced 12 use-after-free reports per run before this change; 0, and no lockdep report, over 1600+ raced iterations after it on bluetooth/master. Fixes: 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode") Cc: stable@vger.kernel.org Reported-by: Siwei Zhang Reviewed-by: Siwei Zhang Signed-off-by: Safa Karakuş Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/af_bluetooth.c | 10 +++++++++ net/bluetooth/iso.c | 9 +++++++- net/bluetooth/l2cap_sock.c | 51 ++++++++++++++++++++++++++++++++++++++------ net/bluetooth/rfcomm/sock.c | 9 +++++++- net/bluetooth/sco.c | 9 +++++++- 5 files changed, 78 insertions(+), 10 deletions(-) (limited to 'net') diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c index 9d68dd86023c..1a6aa3f8d4d6 100644 --- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -340,6 +340,16 @@ restart: if (newsock) sock_graft(sk, newsock); + /* Hand the caller a reference taken while sk is + * still locked. bt_accept_unlink() just dropped + * the accept-queue reference; without this hold a + * concurrent teardown (e.g. l2cap_conn_del() -> + * l2cap_sock_kill()) could free sk between + * release_sock() and the caller using it. Every + * caller drops this with sock_put() when done. + */ + sock_hold(sk); + release_sock(sk); if (next) sock_put(next); diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c index b971281f0a2b..d7af617cda45 100644 --- a/net/bluetooth/iso.c +++ b/net/bluetooth/iso.c @@ -751,6 +751,8 @@ static void iso_sock_cleanup_listen(struct sock *parent) while ((sk = bt_accept_dequeue(parent, NULL))) { iso_sock_close(sk); iso_sock_kill(sk); + /* Drop the reference handed back by bt_accept_dequeue(). */ + sock_put(sk); } /* If listening socket has a hcon, properly disconnect it */ @@ -1356,8 +1358,13 @@ static int iso_sock_accept(struct socket *sock, struct socket *newsock, } ch = bt_accept_dequeue(sk, newsock); - if (ch) + if (ch) { + /* Drop the bridging ref from bt_accept_dequeue(); + * the grafted socket keeps ch alive from here. + */ + sock_put(ch); break; + } if (!timeo) { err = -EAGAIN; diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index cf590a67d364..b34e7da8d906 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -349,8 +349,13 @@ static int l2cap_sock_accept(struct socket *sock, struct socket *newsock, } nsk = bt_accept_dequeue(sk, newsock); - if (nsk) + if (nsk) { + /* Drop the bridging ref from bt_accept_dequeue(); + * the grafted socket keeps nsk alive from here. + */ + sock_put(nsk); break; + } if (!timeo) { err = -EAGAIN; @@ -1475,22 +1480,54 @@ static void l2cap_sock_cleanup_listen(struct sock *parent) BT_DBG("parent %p state %s", parent, state_to_string(parent->sk_state)); - /* Close not yet accepted channels */ + /* Close not yet accepted channels. + * + * bt_accept_dequeue() now returns sk with an extra reference held + * (taken while sk was still locked) so a concurrent l2cap_conn_del() + * -> l2cap_sock_kill() cannot free sk under us. + * + * cleanup_listen() runs under the parent sk lock, so unlike + * l2cap_sock_shutdown() we must NOT take conn->lock here: that would + * establish sk_lock -> conn->lock and invert the established + * conn->lock -> chan->lock -> sk_lock order (lockdep deadlock). + * + * Instead, briefly take the child sk lock to fetch and pin its chan. + * l2cap_conn_del() reaches the chan free only via + * l2cap_chan_del() -> l2cap_sock_teardown_cb(), which itself takes + * the child sk lock; holding it across l2cap_chan_hold_unless_zero() + * therefore guarantees the chan cannot be freed while we read and + * pin it (hold_unless_zero() additionally skips a chan already past + * its last reference). We then drop the sk lock before taking + * chan->lock, so sk and chan locks are never held together. + */ while ((sk = bt_accept_dequeue(parent, NULL))) { - struct l2cap_chan *chan = l2cap_pi(sk)->chan; + struct l2cap_chan *chan; + + lock_sock_nested(sk, L2CAP_NESTING_NORMAL); + chan = l2cap_chan_hold_unless_zero(l2cap_pi(sk)->chan); + release_sock(sk); + if (!chan) { + /* l2cap_conn_del() already tearing this child down */ + sock_put(sk); + continue; + } BT_DBG("child chan %p state %s", chan, state_to_string(chan->state)); - l2cap_chan_hold(chan); l2cap_chan_lock(chan); - __clear_chan_timer(chan); l2cap_chan_close(chan, ECONNRESET); - l2cap_sock_kill(sk); - + /* l2cap_conn_del() may already have killed this socket + * (it sets SOCK_DEAD); skip the duplicate to avoid a + * double sock_put()/l2cap_chan_put(). + */ + if (!sock_flag(sk, SOCK_DEAD)) + l2cap_sock_kill(sk); l2cap_chan_unlock(chan); + l2cap_chan_put(chan); + sock_put(sk); } } diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c index be6639cd6f59..bd7d959c6e9e 100644 --- a/net/bluetooth/rfcomm/sock.c +++ b/net/bluetooth/rfcomm/sock.c @@ -180,6 +180,8 @@ static void rfcomm_sock_cleanup_listen(struct sock *parent) while ((sk = bt_accept_dequeue(parent, NULL))) { rfcomm_sock_close(sk); rfcomm_sock_kill(sk); + /* Drop the reference handed back by bt_accept_dequeue(). */ + sock_put(sk); } parent->sk_state = BT_CLOSED; @@ -497,8 +499,13 @@ static int rfcomm_sock_accept(struct socket *sock, struct socket *newsock, } nsk = bt_accept_dequeue(sk, newsock); - if (nsk) + if (nsk) { + /* Drop the bridging ref from bt_accept_dequeue(); + * the grafted socket keeps nsk alive from here. + */ + sock_put(nsk); break; + } if (!timeo) { err = -EAGAIN; diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index eba44525d41d..f1799c6a6f87 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -502,6 +502,8 @@ static void sco_sock_cleanup_listen(struct sock *parent) while ((sk = bt_accept_dequeue(parent, NULL))) { sco_sock_close(sk); sco_sock_kill(sk); + /* Drop the reference handed back by bt_accept_dequeue(). */ + sock_put(sk); } parent->sk_state = BT_CLOSED; @@ -765,8 +767,13 @@ static int sco_sock_accept(struct socket *sock, struct socket *newsock, } ch = bt_accept_dequeue(sk, newsock); - if (ch) + if (ch) { + /* Drop the bridging ref from bt_accept_dequeue(); + * the grafted socket keeps ch alive from here. + */ + sock_put(ch); break; + } if (!timeo) { err = -EAGAIN; -- cgit v1.2.3 From 5f17ae0f595aeb560155ce98edbe44d3eacc7e40 Mon Sep 17 00:00:00 2001 From: Alice Mikityanska Date: Mon, 18 May 2026 09:22:49 +0300 Subject: udp: gso: Fix handling checksum in __udp_gso_segment The cited commit started using msslen for uh->len, but still uses newlen to adjust uh->check. Although the checksum is ignored in most cases due to the hardware offload, __udp_gso_segment attempts to maintain the correct one. Fix uh->check and adjust it by the right value. Additionally, after the fix, newlen becomes assigned and unused before the loop. The code can be simplified a bit if mss adjustment is dropped, so that newlen becomes equal to msslen before the loop, and msslen can be also dropped, saving a few lines of code. This brings us back to one variable, drops an unneeded arithmetic for mss, and fixes the UDP checksum. Fixes: b10b446ce7ad ("udp: gso: Use single MSS length in UDP header for GSO_PARTIAL") Signed-off-by: Alice Mikityanska Reviewed-by: Willem de Bruijn Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20260518062250.3019914-2-gal@nvidia.com Signed-off-by: Jakub Kicinski --- net/ipv4/udp_offload.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) (limited to 'net') diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index a0813d425b71..2578aa7f9ff9 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -482,11 +482,11 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, struct sock *sk = gso_skb->sk; unsigned int sum_truesize = 0; struct sk_buff *segs, *seg; - __be16 newlen, msslen; struct udphdr *uh; unsigned int mss; bool copy_dtor; __sum16 check; + __be16 newlen; int ret = 0; mss = skb_shinfo(gso_skb)->gso_size; @@ -555,15 +555,6 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, return segs; } - msslen = htons(sizeof(*uh) + mss); - - /* GSO partial and frag_list segmentation only requires splitting - * the frame into an MSS multiple and possibly a remainder, both - * cases return a GSO skb. So update the mss now. - */ - if (skb_is_gso(segs)) - mss *= skb_shinfo(segs)->gso_segs; - seg = segs; uh = udp_hdr(seg); @@ -586,7 +577,7 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, if (!seg->next) break; - uh->len = msslen; + uh->len = newlen; uh->check = check; if (seg->ip_summed == CHECKSUM_PARTIAL) -- cgit v1.2.3 From 78effd896eee11ac9db9bcbb53e7bbcad96073d7 Mon Sep 17 00:00:00 2001 From: Gal Pressman Date: Mon, 18 May 2026 09:22:50 +0300 Subject: udp: Fix UDP length on last GSO_PARTIAL segment Following the cited commit, __udp_gso_segment() writes single MSS length in the UDP header. The cited patch doesn't account for the fact that the last segment could be a GSO skb by itself. This could happen when the size of the packet is a multiple of MSS, hence the first segment is also the last one (there is no need for a remainder skb). When the post-loop segment is a GSO skb, assign the single MSS length in the UDP header. Fixes: b10b446ce7ad ("udp: gso: Use single MSS length in UDP header for GSO_PARTIAL") Reported-by: Matthew Schwartz Closes: https://lore.kernel.org/all/6c3fb15e-711d-4b8d-b152-e03d9b05293f@linux.dev/ Tested-by: Matthew Schwartz Reviewed-by: Dragos Tatulea Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20260518062250.3019914-3-gal@nvidia.com Signed-off-by: Jakub Kicinski --- net/ipv4/udp_offload.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 2578aa7f9ff9..29651b1a0bc7 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -590,9 +590,12 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, uh = udp_hdr(seg); } - /* last packet can be partial gso_size, account for that in checksum */ - newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) + - seg->data_len); + /* Unless skb fits perfectly as GSO_PARTIAL, the trailing + * segment may not be full MSS, account for that in the checksum + */ + if (!skb_is_gso(seg)) + newlen = htons(skb_tail_pointer(seg) - + skb_transport_header(seg) + seg->data_len); check = csum16_add(csum16_sub(uh->check, uh->len), newlen); uh->len = newlen; -- cgit v1.2.3 From a3442936dd0523277e20aaf86207c574e755c634 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 15 May 2026 15:13:24 -0700 Subject: net: shaper: annotate the data races As previously discussed we don't care about making the shaper state fully RCU-compliant because the hierarchy itself can't be dumped in one go over Netlink. Let's annotate the reads and writes to make that clear. The field-by-field assignments will also be useful for the next commit which adds explicit "valid" field (which we don't want to override with the current full struct assignment). Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260515221325.1685455-2-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/shaper/shaper.c | 53 ++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 38 insertions(+), 15 deletions(-) (limited to 'net') diff --git a/net/shaper/shaper.c b/net/shaper/shaper.c index b1c65110f04d..520cefdc3d90 100644 --- a/net/shaper/shaper.c +++ b/net/shaper/shaper.c @@ -138,35 +138,58 @@ handle_nest_cancel: return -EMSGSIZE; } +static void net_shaper_copy(struct net_shaper *dst, + const struct net_shaper *src) +{ + WRITE_ONCE(dst->parent.scope, READ_ONCE(src->parent.scope)); + WRITE_ONCE(dst->parent.id, READ_ONCE(src->parent.id)); + WRITE_ONCE(dst->handle.scope, READ_ONCE(src->handle.scope)); + WRITE_ONCE(dst->handle.id, READ_ONCE(src->handle.id)); + + WRITE_ONCE(dst->metric, READ_ONCE(src->metric)); + WRITE_ONCE(dst->bw_min, READ_ONCE(src->bw_min)); + WRITE_ONCE(dst->bw_max, READ_ONCE(src->bw_max)); + WRITE_ONCE(dst->burst, READ_ONCE(src->burst)); + WRITE_ONCE(dst->priority, READ_ONCE(src->priority)); + WRITE_ONCE(dst->weight, READ_ONCE(src->weight)); + + /* private fields are only used on the write path under the lock */ + data_race(dst->leaves = src->leaves); +} + static int net_shaper_fill_one(struct sk_buff *msg, const struct net_shaper_binding *binding, const struct net_shaper *shaper, const struct genl_info *info) { + struct net_shaper cur; void *hdr; hdr = genlmsg_iput(msg, info); if (!hdr) return -EMSGSIZE; + /* Make a copy to avoid data races */ + net_shaper_copy(&cur, shaper); + if (net_shaper_fill_binding(msg, binding, NET_SHAPER_A_IFINDEX) || - net_shaper_fill_handle(msg, &shaper->parent, + net_shaper_fill_handle(msg, &cur.parent, NET_SHAPER_A_PARENT) || - net_shaper_fill_handle(msg, &shaper->handle, + net_shaper_fill_handle(msg, &cur.handle, NET_SHAPER_A_HANDLE) || - ((shaper->bw_min || shaper->bw_max || shaper->burst) && - nla_put_u32(msg, NET_SHAPER_A_METRIC, shaper->metric)) || - (shaper->bw_min && - nla_put_uint(msg, NET_SHAPER_A_BW_MIN, shaper->bw_min)) || - (shaper->bw_max && - nla_put_uint(msg, NET_SHAPER_A_BW_MAX, shaper->bw_max)) || - (shaper->burst && - nla_put_uint(msg, NET_SHAPER_A_BURST, shaper->burst)) || - (shaper->priority && - nla_put_u32(msg, NET_SHAPER_A_PRIORITY, shaper->priority)) || - (shaper->weight && - nla_put_u32(msg, NET_SHAPER_A_WEIGHT, shaper->weight))) + ((cur.bw_min || cur.bw_max || cur.burst) && + nla_put_u32(msg, NET_SHAPER_A_METRIC, cur.metric)) || + (cur.bw_min && + nla_put_uint(msg, NET_SHAPER_A_BW_MIN, cur.bw_min)) || + (cur.bw_max && + nla_put_uint(msg, NET_SHAPER_A_BW_MAX, cur.bw_max)) || + (cur.burst && + nla_put_uint(msg, NET_SHAPER_A_BURST, cur.burst)) || + (cur.priority && + nla_put_u32(msg, NET_SHAPER_A_PRIORITY, cur.priority)) || + (cur.weight && + nla_put_u32(msg, NET_SHAPER_A_WEIGHT, cur.weight))) goto nla_put_failure; genlmsg_end(msg, hdr); @@ -424,7 +447,7 @@ static void net_shaper_commit(struct net_shaper_binding *binding, /* Successful update: drop the tentative mark * and update the hierarchy container. */ - *cur = shapers[i]; + net_shaper_copy(cur, &shapers[i]); smp_wmb(); __xa_set_mark(&hierarchy->shapers, index, NET_SHAPER_VALID); } -- cgit v1.2.3 From b8d7519352ba8c6df83259295d4a3bad093cae90 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 15 May 2026 15:13:25 -0700 Subject: net: shaper: rework the VALID marking (again) Recent commit changed the semantics from NOT_VALID to VALID. I didn't realize that the flags are not stored atomically with the entry in XArray. There's still a race of reader observing a VALID mark for a slot, getting interrupted, writer replacing the entry with a different one, reader continuing, fetching the entry which is now a different pointer than the pointer for which VALID was meant. The biggest consequence of this is that we may see a UAF since net_shaper_rollback() assumed that entries without VALID can be freed without observing RCU. Looks like the XArray marks are buying us nothing at this point. Let's convert the code to an explicit valid field. The smp_load_acquire() / smp_store_release() barriers are marginally cleaner. Reported-by: Sashiko Fixes: 93954b40f6a4 ("net-shapers: implement NL set and delete operations") Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260515221325.1685455-3-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/shaper/shaper.c | 45 ++++++++++++++++++--------------------------- 1 file changed, 18 insertions(+), 27 deletions(-) (limited to 'net') diff --git a/net/shaper/shaper.c b/net/shaper/shaper.c index 520cefdc3d90..dea9270f3e57 100644 --- a/net/shaper/shaper.c +++ b/net/shaper/shaper.c @@ -306,31 +306,24 @@ static void net_shaper_default_parent(const struct net_shaper_handle *handle, parent->id = 0; } -/* MARK_0 is already in use due to XA_FLAGS_ALLOC. The VALID mark is set on - * an entry only after the device-side configuration has completed - * successfully (see net_shaper_commit()). Lookups and dumps must filter on - * this mark to avoid exposing tentative entries inserted by - * net_shaper_pre_insert() while the driver call is still in flight. - */ -#define NET_SHAPER_VALID XA_MARK_1 - static struct net_shaper * net_shaper_lookup(struct net_shaper_binding *binding, const struct net_shaper_handle *handle) { u32 index = net_shaper_handle_to_index(handle); struct net_shaper_hierarchy *hierarchy; + struct net_shaper *cur; hierarchy = net_shaper_hierarchy_rcu(binding); - if (!hierarchy || !xa_get_mark(&hierarchy->shapers, index, - NET_SHAPER_VALID)) + if (!hierarchy) return NULL; - /* Pairs with smp_wmb() in net_shaper_commit(): if the entry is - * valid, its contents must be visible too. - */ - smp_rmb(); - return xa_load(&hierarchy->shapers, index); + cur = xa_load(&hierarchy->shapers, index); + /* Check valid before reading fields */ + if (!cur || !smp_load_acquire(&cur->valid)) + return NULL; + + return cur; } /* Allocate on demand the per device shaper's hierarchy container. @@ -444,12 +437,10 @@ static void net_shaper_commit(struct net_shaper_binding *binding, if (WARN_ON_ONCE(!cur)) continue; - /* Successful update: drop the tentative mark - * and update the hierarchy container. - */ + /* Successful update: update the hierarchy container... */ net_shaper_copy(cur, &shapers[i]); - smp_wmb(); - __xa_set_mark(&hierarchy->shapers, index, NET_SHAPER_VALID); + /* ... publish to lockless readers. */ + smp_store_release(&cur->valid, true); } xa_unlock(&hierarchy->shapers); } @@ -466,10 +457,10 @@ static void net_shaper_rollback(struct net_shaper_binding *binding) xa_lock(&hierarchy->shapers); xa_for_each(&hierarchy->shapers, index, cur) { - if (xa_get_mark(&hierarchy->shapers, index, NET_SHAPER_VALID)) + if (cur->valid) continue; __xa_erase(&hierarchy->shapers, index); - kfree(cur); + kfree_rcu(cur, rcu); } xa_unlock(&hierarchy->shapers); } @@ -882,12 +873,12 @@ int net_shaper_nl_get_dumpit(struct sk_buff *skb, goto out_unlock; for (; (shaper = xa_find(&hierarchy->shapers, &ctx->start_index, - U32_MAX, NET_SHAPER_VALID)); + U32_MAX, XA_PRESENT)); ctx->start_index++) { - /* Pairs with smp_wmb() in net_shaper_commit(): the entry - * is marked VALID, so its contents must be visible too. - */ - smp_rmb(); + /* Check valid before reading fields */ + if (!smp_load_acquire(&shaper->valid)) + continue; + ret = net_shaper_fill_one(skb, binding, shaper, info); if (ret) break; -- cgit v1.2.3 From 2b50aceafe6606ea52ed42aadd1b4d44a188aade Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 16 May 2026 00:05:13 +0100 Subject: crypto/krb5, rxrpc: Fix lack of pre-decrypt/pre-verify length checks Change the krb5 crypto library to provide facilities to precheck the length of the message about to be decrypted or verified. Fix AF_RXRPC to make use of this to validate DATA packets secured with RxGK. Fixes: 9d1d2b59341f ("rxrpc: rxgk: Implement the yfs-rxgk security class (GSSAPI)") Closes: https://sashiko.dev/#/patchset/20260511160753.607296-1-dhowells%40redhat.com Signed-off-by: David Howells cc: Herbert Xu cc: Simon Horman cc: Chuck Lever cc: linux-afs@lists.infradead.org Reviewed-by: Jeffrey Altman Tested-by: Marc Dionne Link: https://patch.msgid.link/20260515230516.2718212-2-dhowells@redhat.com Signed-off-by: Jakub Kicinski --- net/rxrpc/rxgk.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/rxrpc/rxgk.c b/net/rxrpc/rxgk.c index 0d5e654da918..26e723052a37 100644 --- a/net/rxrpc/rxgk.c +++ b/net/rxrpc/rxgk.c @@ -480,8 +480,12 @@ static int rxgk_verify_packet_integrity(struct rxrpc_call *call, _enter(""); - crypto_krb5_where_is_the_data(gk->krb5, KRB5_CHECKSUM_MODE, - &data_offset, &data_len); + if (crypto_krb5_where_is_the_data(gk->krb5, KRB5_CHECKSUM_MODE, + &data_offset, &data_len) < 0) { + ret = rxrpc_abort_eproto(call, skb, RXGK_PACKETSHORT, + rxgk_abort_1_short_header); + goto put_gk; + } hdr = kzalloc_obj(*hdr, GFP_NOFS); if (!hdr) @@ -529,6 +533,13 @@ static int rxgk_verify_packet_encrypted(struct rxrpc_call *call, _enter(""); + if (crypto_krb5_check_data_len(gk->krb5, KRB5_ENCRYPT_MODE, + len, sizeof(hdr)) < 0) { + ret = rxrpc_abort_eproto(call, skb, RXGK_PACKETSHORT, + rxgk_abort_2_short_header); + goto error; + } + ret = rxgk_decrypt_skb(gk->krb5, gk->rx_enc, skb, &offset, &len, &ac); if (ret < 0) { if (ret != -ENOMEM) -- cgit v1.2.3 From d2bc90cf6c75cb96d2ce549be6c35efa3099d25b Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 16 May 2026 00:05:14 +0100 Subject: rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg This improves the fix for CVE-2026-43500. Fix the pagecache corruption from in-place decryption of a DATA packet transmitted locally by splice() by getting rid of the packet sharing in the I/O thread and unconditionally extracting the packet content into a bounce buffer in which the buffer is decrypted. recvmsg() (or the kernel equivalent) then copies the data from the bounce buffer to the destination buffer. The sk_buff then remains unmodified. This has an additional advantage in that the packet is then arranged in the buffer with the correct alignment required for the crypto algorithms to process directly. The performance of the crypto does seem to be a little faster and, surprisingly, the unencrypted performance doesn't seem to change much - possibly due to removing complexity from the I/O thread. Yet another advantage is that the I/O thread doesn't have to copy packets which would slow down packet distribution, ACK generation, etc.. The buffer belongs to the call and is allocated initially at 2K, sufficiently large to hold a whole jumbo subpacket, but the buffer will be increased in size if needed. However, to take this work, MSG_PEEK may cause a later packet to be decrypted into the buffer, in which case the earlier one will need re-decrypting for a subsequent recvmsg(). Note that rx_pkt_offset may legitimately see 0 as a valid offset now, so switch to using USHRT_MAX to indicate an invalid offset. Note also that I would generally prefer to replace the buffers of the current sk_buff with a new kmalloc'd buffer of the right size, ditching the old data and frags as this makes the handling of MSG_PEEK easier and removes the re-decryption issue, but this looks like quite a complicated thing to achieve. skb_morph() looks half way to what I want, but I don't want to have to allocate a new sk_buff. Fixes: d0d5c0cd1e71 ("rxrpc: Use skb_unshare() rather than skb_cow_data()") Reported-by: Hyunwoo Kim Closes: https://lore.kernel.org/r/afKV2zGR6rrelPC7@v4bel/ Signed-off-by: David Howells cc: Simon Horman cc: Jiayuan Chen cc: linux-afs@lists.infradead.org Reviewed-by: Jeffrey Altman Tested-by: Marc Dionne Link: https://patch.msgid.link/20260515230516.2718212-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski --- net/rxrpc/ar-internal.h | 7 ++-- net/rxrpc/call_event.c | 22 +------------ net/rxrpc/call_object.c | 2 ++ net/rxrpc/insecure.c | 3 -- net/rxrpc/recvmsg.c | 68 ++++++++++++++++++++++++++++++-------- net/rxrpc/rxgk.c | 51 ++++++++++++++--------------- net/rxrpc/rxgk_common.h | 82 ++++++++++++++++++++++++++++++++++++++++++++++ net/rxrpc/rxkad.c | 86 ++++++++++++++++++------------------------------- 8 files changed, 201 insertions(+), 120 deletions(-) (limited to 'net') diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 27c2aa2dd023..783367eea798 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -213,8 +213,6 @@ struct rxrpc_skb_priv { struct { u16 offset; /* Offset of data */ u16 len; /* Length of data */ - u8 flags; -#define RXRPC_RX_VERIFIED 0x01 }; struct { rxrpc_seq_t first_ack; /* First packet in acks table */ @@ -774,6 +772,11 @@ struct rxrpc_call { struct sk_buff_head recvmsg_queue; /* Queue of packets ready for recvmsg() */ struct sk_buff_head rx_queue; /* Queue of packets for this call to receive */ struct sk_buff_head rx_oos_queue; /* Queue of out of sequence packets */ + void *rx_dec_buffer; /* Decryption buffer */ + unsigned short rx_dec_bsize; /* rx_dec_buffer size */ + unsigned short rx_dec_offset; /* Decrypted packet data offset */ + unsigned short rx_dec_len; /* Decrypted packet data len */ + rxrpc_seq_t rx_dec_seq; /* Packet in decryption buffer */ rxrpc_seq_t rx_highest_seq; /* Higest sequence number received */ rxrpc_seq_t rx_consumed; /* Highest packet consumed */ diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c index 2b19b252225e..fec59d9338b9 100644 --- a/net/rxrpc/call_event.c +++ b/net/rxrpc/call_event.c @@ -332,27 +332,7 @@ bool rxrpc_input_call_event(struct rxrpc_call *call) saw_ack |= sp->hdr.type == RXRPC_PACKET_TYPE_ACK; - if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA && - sp->hdr.securityIndex != 0 && - (skb_cloned(skb) || - skb_has_frag_list(skb) || - skb_has_shared_frag(skb))) { - /* Unshare the packet so that it can be - * modified by in-place decryption. - */ - struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC); - - if (nskb) { - rxrpc_new_skb(nskb, rxrpc_skb_new_unshared); - rxrpc_input_call_packet(call, nskb); - rxrpc_free_skb(nskb, rxrpc_skb_put_call_rx); - } else { - /* OOM - Drop the packet. */ - rxrpc_see_skb(skb, rxrpc_skb_see_unshare_nomem); - } - } else { - rxrpc_input_call_packet(call, skb); - } + rxrpc_input_call_packet(call, skb); rxrpc_free_skb(skb, rxrpc_skb_put_call_rx); did_receive = true; } diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c index f035f486c139..fcb9d38bb521 100644 --- a/net/rxrpc/call_object.c +++ b/net/rxrpc/call_object.c @@ -152,6 +152,7 @@ struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp, spin_lock_init(&call->notify_lock); refcount_set(&call->ref, 1); call->debug_id = debug_id; + call->rx_pkt_offset = USHRT_MAX; call->tx_total_len = -1; call->tx_jumbo_max = 1; call->next_rx_timo = 20 * HZ; @@ -553,6 +554,7 @@ static void rxrpc_cleanup_rx_buffers(struct rxrpc_call *call) rxrpc_purge_queue(&call->recvmsg_queue); rxrpc_purge_queue(&call->rx_queue); rxrpc_purge_queue(&call->rx_oos_queue); + kfree(call->rx_dec_buffer); } /* diff --git a/net/rxrpc/insecure.c b/net/rxrpc/insecure.c index 0a260df45d25..7a26c6097d03 100644 --- a/net/rxrpc/insecure.c +++ b/net/rxrpc/insecure.c @@ -32,9 +32,6 @@ static int none_secure_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb) static int none_verify_packet(struct rxrpc_call *call, struct sk_buff *skb) { - struct rxrpc_skb_priv *sp = rxrpc_skb(skb); - - sp->flags |= RXRPC_RX_VERIFIED; return 0; } diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c index e1f7513a46db..c940600117a4 100644 --- a/net/rxrpc/recvmsg.c +++ b/net/rxrpc/recvmsg.c @@ -147,15 +147,52 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call) } /* - * Decrypt and verify a DATA packet. + * Decrypt and verify a DATA packet. The content of the packet is pulled out + * into a flat buffer rather than decrypting in place in the skbuff. This also + * has the advantage of aligning the buffer correctly for the crypto routines. + * + * We keep track of the sequence number of the packet currently decrypted into + * the buffer in ->rx_dec_seq. If MSG_PEEK is used and steps onto a new + * packet, subsequent recvmsg() calls will have to go back and re-decrypt the + * current packet. */ static int rxrpc_verify_data(struct rxrpc_call *call, struct sk_buff *skb) { struct rxrpc_skb_priv *sp = rxrpc_skb(skb); + int ret; - if (sp->flags & RXRPC_RX_VERIFIED) - return 0; - return call->security->verify_packet(call, skb); + if (sp->len > call->rx_dec_bsize) { + /* Make sure we can hold a 1412-byte jumbo subpacket and make + * sure that the buffer size is aligned to a crypto blocksize. + */ + size_t size = clamp(round_up(sp->len, 32), 2048, 65535); + void *buffer = krealloc(call->rx_dec_buffer, size, GFP_NOFS); + + if (!buffer) + return -ENOMEM; + call->rx_dec_buffer = buffer; + call->rx_dec_bsize = size; + } + + ret = -EFAULT; + if (skb_copy_bits(skb, sp->offset, call->rx_dec_buffer, sp->len) < 0) + goto err; + + call->rx_dec_offset = 0; + call->rx_dec_len = sp->len; + call->rx_dec_seq = sp->hdr.seq; + ret = call->security->verify_packet(call, skb); + if (ret < 0) + goto err; + return 0; + +err: + kfree(call->rx_dec_buffer); + call->rx_dec_buffer = NULL; + call->rx_dec_bsize = 0; + call->rx_dec_offset = 0; + call->rx_dec_len = 0; + return ret; } /* @@ -283,16 +320,21 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call, if (msg) sock_recv_timestamp(msg, sock->sk, skb); - if (rx_pkt_offset == 0) { + if (call->rx_dec_seq != sp->hdr.seq || + !call->rx_dec_buffer) { ret2 = rxrpc_verify_data(call, skb); trace_rxrpc_recvdata(call, rxrpc_recvmsg_next, seq, - sp->offset, sp->len, ret2); + call->rx_dec_offset, + call->rx_dec_len, ret2); if (ret2 < 0) { ret = ret2; goto out; } - rx_pkt_offset = sp->offset; - rx_pkt_len = sp->len; + } + + if (rx_pkt_offset == USHRT_MAX) { + rx_pkt_offset = call->rx_dec_offset; + rx_pkt_len = call->rx_dec_len; } else { trace_rxrpc_recvdata(call, rxrpc_recvmsg_cont, seq, rx_pkt_offset, rx_pkt_len, 0); @@ -304,10 +346,10 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call, if (copy > remain) copy = remain; if (copy > 0) { - ret2 = skb_copy_datagram_iter(skb, rx_pkt_offset, iter, - copy); - if (ret2 < 0) { - ret = ret2; + ret2 = copy_to_iter(call->rx_dec_buffer + rx_pkt_offset, + copy, iter); + if (ret2 != copy) { + ret = -EFAULT; goto out; } @@ -328,7 +370,7 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call, /* The whole packet has been transferred. */ if (sp->hdr.flags & RXRPC_LAST_PACKET) ret = 1; - rx_pkt_offset = 0; + rx_pkt_offset = USHRT_MAX; rx_pkt_len = 0; skb = skb_peek_next(skb, &call->recvmsg_queue); diff --git a/net/rxrpc/rxgk.c b/net/rxrpc/rxgk.c index 26e723052a37..f81703ee7ac3 100644 --- a/net/rxrpc/rxgk.c +++ b/net/rxrpc/rxgk.c @@ -473,8 +473,9 @@ static int rxgk_verify_packet_integrity(struct rxrpc_call *call, struct rxrpc_skb_priv *sp = rxrpc_skb(skb); struct rxgk_header *hdr; struct krb5_buffer metadata; - unsigned int offset = sp->offset, len = sp->len; + unsigned int len = call->rx_dec_len; size_t data_offset = 0, data_len = len; + void *data = call->rx_dec_buffer, *p = data; u32 ac = 0; int ret = -ENOMEM; @@ -500,16 +501,15 @@ static int rxgk_verify_packet_integrity(struct rxrpc_call *call, metadata.len = sizeof(*hdr); metadata.data = hdr; - ret = rxgk_verify_mic_skb(gk->krb5, gk->rx_Kc, &metadata, - skb, &offset, &len, &ac); + ret = rxgk_verify_mic(gk->krb5, gk->rx_Kc, &metadata, &p, &len, &ac); kfree(hdr); if (ret < 0) { if (ret != -ENOMEM) rxrpc_abort_eproto(call, skb, ac, rxgk_abort_1_verify_mic_eproto); } else { - sp->offset = offset; - sp->len = len; + call->rx_dec_offset = p - data; + call->rx_dec_len = len; } put_gk: @@ -526,56 +526,53 @@ static int rxgk_verify_packet_encrypted(struct rxrpc_call *call, struct sk_buff *skb) { struct rxrpc_skb_priv *sp = rxrpc_skb(skb); - struct rxgk_header hdr; - unsigned int offset = sp->offset, len = sp->len; + struct rxgk_header *hdr; + unsigned int offset = 0, len = call->rx_dec_len; + void *data = call->rx_dec_buffer, *p = data; int ret; u32 ac = 0; _enter(""); if (crypto_krb5_check_data_len(gk->krb5, KRB5_ENCRYPT_MODE, - len, sizeof(hdr)) < 0) { + len, sizeof(*hdr)) < 0) { ret = rxrpc_abort_eproto(call, skb, RXGK_PACKETSHORT, rxgk_abort_2_short_header); goto error; } - ret = rxgk_decrypt_skb(gk->krb5, gk->rx_enc, skb, &offset, &len, &ac); + ret = rxgk_decrypt(gk->krb5, gk->rx_enc, &p, &len, &ac); if (ret < 0) { if (ret != -ENOMEM) rxrpc_abort_eproto(call, skb, ac, rxgk_abort_2_decrypt_eproto); goto error; } + offset = p - data; - if (len < sizeof(hdr)) { + if (len < sizeof(*hdr)) { ret = rxrpc_abort_eproto(call, skb, RXGK_PACKETSHORT, rxgk_abort_2_short_header); goto error; } /* Extract the header from the skb */ - ret = skb_copy_bits(skb, offset, &hdr, sizeof(hdr)); - if (ret < 0) { - ret = rxrpc_abort_eproto(call, skb, RXGK_PACKETSHORT, - rxgk_abort_2_short_encdata); - goto error; - } - offset += sizeof(hdr); - len -= sizeof(hdr); - - if (ntohl(hdr.epoch) != call->conn->proto.epoch || - ntohl(hdr.cid) != call->cid || - ntohl(hdr.call_number) != call->call_id || - ntohl(hdr.seq) != sp->hdr.seq || - ntohl(hdr.sec_index) != call->security_ix || - ntohl(hdr.data_len) > len) { + hdr = data + offset; + offset += sizeof(*hdr); + len -= sizeof(*hdr); + + if (ntohl(hdr->epoch) != call->conn->proto.epoch || + ntohl(hdr->cid) != call->cid || + ntohl(hdr->call_number) != call->call_id || + ntohl(hdr->seq) != sp->hdr.seq || + ntohl(hdr->sec_index) != call->security_ix || + ntohl(hdr->data_len) > len) { ret = rxrpc_abort_eproto(call, skb, RXGK_SEALEDINCON, rxgk_abort_2_short_data); goto error; } - sp->offset = offset; - sp->len = ntohl(hdr.data_len); + call->rx_dec_offset = offset; + call->rx_dec_len = ntohl(hdr->data_len); ret = 0; error: rxgk_put(gk); diff --git a/net/rxrpc/rxgk_common.h b/net/rxrpc/rxgk_common.h index 1e257d7ab8ec..112b5366ce11 100644 --- a/net/rxrpc/rxgk_common.h +++ b/net/rxrpc/rxgk_common.h @@ -105,6 +105,49 @@ int rxgk_decrypt_skb(const struct krb5_enctype *krb5, return ret; } +/* + * Apply decryption and checksumming functions a flat data buffer. The data + * point and length are updated to reflect the actual content of the encrypted + * region. + */ +static inline int rxgk_decrypt(const struct krb5_enctype *krb5, + struct crypto_aead *aead, + void **_data, unsigned int *_len, + int *_error_code) +{ + struct scatterlist sg[1]; + size_t offset = 0, len = *_len; + int ret; + + sg_init_one(sg, *_data, len); + + ret = crypto_krb5_decrypt(krb5, aead, sg, 1, &offset, &len); + switch (ret) { + case 0: + if (offset & 3) { + *_error_code = RXGK_INCONSISTENCY; + ret = -EPROTO; + break; + } + *_data += offset; + *_len = len; + break; + case -EBADMSG: /* Checksum mismatch. */ + case -EPROTO: + *_error_code = RXGK_SEALEDINCON; + break; + case -EMSGSIZE: + *_error_code = RXGK_PACKETSHORT; + break; + case -ENOPKG: /* Would prefer RXGK_BADETYPE, but not available for YFS. */ + default: + *_error_code = RXGK_INCONSISTENCY; + break; + } + + return ret; +} + /* * Check the MIC on a region of an skbuff. The offset and length are updated * to reflect the actual content of the secure region. @@ -148,3 +191,42 @@ int rxgk_verify_mic_skb(const struct krb5_enctype *krb5, return ret; } + +/* + * Check the MIC on a flat buffer. The data pointer and length are updated to + * reflect the actual content of the secure region. + */ +static inline +int rxgk_verify_mic(const struct krb5_enctype *krb5, + struct crypto_shash *shash, + const struct krb5_buffer *metadata, + void **_data, unsigned int *_len, + u32 *_error_code) +{ + struct scatterlist sg[1]; + size_t offset = 0, len = *_len; + int ret; + + sg_init_one(sg, *_data, len); + + ret = crypto_krb5_verify_mic(krb5, shash, metadata, sg, 1, &offset, &len); + switch (ret) { + case 0: + *_data += offset; + *_len = len; + break; + case -EBADMSG: /* Checksum mismatch */ + case -EPROTO: + *_error_code = RXGK_SEALEDINCON; + break; + case -EMSGSIZE: + *_error_code = RXGK_PACKETSHORT; + break; + case -ENOPKG: /* Would prefer RXGK_BADETYPE, but not available for YFS. */ + default: + *_error_code = RXGK_INCONSISTENCY; + break; + } + + return ret; +} diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c index cba7935977f0..075936337836 100644 --- a/net/rxrpc/rxkad.c +++ b/net/rxrpc/rxkad.c @@ -430,27 +430,25 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb, rxrpc_seq_t seq, struct skcipher_request *req) { - struct rxkad_level1_hdr sechdr; + struct rxkad_level1_hdr *sechdr; struct rxrpc_skb_priv *sp = rxrpc_skb(skb); struct rxrpc_crypt iv; - struct scatterlist sg[16]; - u32 data_size, buf; + struct scatterlist sg[1]; + void *data = call->rx_dec_buffer; + u32 len = sp->len, data_size, buf; u16 check; int ret; _enter(""); - if (sp->len < 8) + if (len < 8) return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON, rxkad_abort_1_short_header); /* Decrypt the skbuff in-place. TODO: We really want to decrypt * directly into the target buffer. */ - sg_init_table(sg, ARRAY_SIZE(sg)); - ret = skb_to_sgvec(skb, sg, sp->offset, 8); - if (unlikely(ret < 0)) - return ret; + sg_init_one(sg, data, len); /* start the decryption afresh */ memset(&iv, 0, sizeof(iv)); @@ -464,13 +462,11 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb, return ret; /* Extract the decrypted packet length */ - if (skb_copy_bits(skb, sp->offset, &sechdr, sizeof(sechdr)) < 0) - return rxrpc_abort_eproto(call, skb, RXKADDATALEN, - rxkad_abort_1_short_encdata); - sp->offset += sizeof(sechdr); - sp->len -= sizeof(sechdr); + sechdr = data; + call->rx_dec_offset = sizeof(*sechdr); + len -= sizeof(*sechdr); - buf = ntohl(sechdr.data_size); + buf = ntohl(sechdr->data_size); data_size = buf & 0xffff; check = buf >> 16; @@ -479,10 +475,10 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb, if (check != 0) return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON, rxkad_abort_1_short_check); - if (data_size > sp->len) + if (data_size > len) return rxrpc_abort_eproto(call, skb, RXKADDATALEN, rxkad_abort_1_short_data); - sp->len = data_size; + call->rx_dec_len = data_size; _leave(" = 0 [dlen=%x]", data_size); return 0; @@ -496,43 +492,28 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb, struct skcipher_request *req) { const struct rxrpc_key_token *token; - struct rxkad_level2_hdr sechdr; + struct rxkad_level2_hdr *sechdr; struct rxrpc_skb_priv *sp = rxrpc_skb(skb); struct rxrpc_crypt iv; - struct scatterlist _sg[4], *sg; - u32 data_size, buf; + struct scatterlist sg[1]; + void *data = call->rx_dec_buffer; + u32 len = sp->len, data_size, buf; u16 check; - int nsg, ret; + int ret; - _enter(",{%d}", sp->len); + _enter(",{%d}", len); - if (sp->len < 8) + if (len < 8) return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON, rxkad_abort_2_short_header); /* Don't let the crypto algo see a misaligned length. */ - sp->len = round_down(sp->len, 8); + len = round_down(len, 8); - /* Decrypt the skbuff in-place. TODO: We really want to decrypt - * directly into the target buffer. + /* Decrypt in place in the call's decryption buffer. TODO: We really + * want to decrypt directly into the target buffer. */ - sg = _sg; - nsg = skb_shinfo(skb)->nr_frags + 1; - if (nsg <= 4) { - nsg = 4; - } else { - sg = kmalloc_objs(*sg, nsg, GFP_NOIO); - if (!sg) - return -ENOMEM; - } - - sg_init_table(sg, nsg); - ret = skb_to_sgvec(skb, sg, sp->offset, sp->len); - if (unlikely(ret < 0)) { - if (sg != _sg) - kfree(sg); - return ret; - } + sg_init_one(sg, data, len); /* decrypt from the session key */ token = call->conn->key->payload.data[0]; @@ -540,11 +521,9 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb, skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher); skcipher_request_set_callback(req, 0, NULL, NULL); - skcipher_request_set_crypt(req, sg, sg, sp->len, iv.x); + skcipher_request_set_crypt(req, sg, sg, len, iv.x); ret = crypto_skcipher_decrypt(req); skcipher_request_zero(req); - if (sg != _sg) - kfree(sg); if (ret < 0) { if (ret == -ENOMEM) return ret; @@ -553,13 +532,11 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb, } /* Extract the decrypted packet length */ - if (skb_copy_bits(skb, sp->offset, &sechdr, sizeof(sechdr)) < 0) - return rxrpc_abort_eproto(call, skb, RXKADDATALEN, - rxkad_abort_2_short_len); - sp->offset += sizeof(sechdr); - sp->len -= sizeof(sechdr); + sechdr = data; + call->rx_dec_offset = sizeof(*sechdr); + len -= sizeof(*sechdr); - buf = ntohl(sechdr.data_size); + buf = ntohl(sechdr->data_size); data_size = buf & 0xffff; check = buf >> 16; @@ -569,17 +546,18 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb, return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON, rxkad_abort_2_short_check); - if (data_size > sp->len) + if (data_size > len) return rxrpc_abort_eproto(call, skb, RXKADDATALEN, rxkad_abort_2_short_data); - sp->len = data_size; + call->rx_dec_len = data_size; _leave(" = 0 [dlen=%x]", data_size); return 0; } /* - * Verify the security on a received packet and the subpackets therein. + * Verify the security on a received (sub)packet. If the packet needs + * modifying (e.g. decrypting), it must be copied. */ static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb) { -- cgit v1.2.3 From 8bfab4b6ffc2fe92da86300728fc8c3c7ebffb56 Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 16 May 2026 00:05:15 +0100 Subject: rxrpc: Fix RESPONSE packet verification to extract skb to a linear buffer This improves the fix for CVE-2026-43500. Fix the verification of RESPONSE packets to avoid the problem of overwriting a RESPONSE packet sent via splice to a local address by extracting the contents of the UDP packet into a kmalloc'd linear buffer rather than decrypting the data in place in the sk_buff (which may corrupt the original buffer). Fixes: 24481a7f5733 ("rxrpc: Fix conn-level packet handling to unshare RESPONSE packets") Reported-by: Hyunwoo Kim Closes: https://lore.kernel.org/r/afKV2zGR6rrelPC7@v4bel/ Signed-off-by: David Howells cc: Simon Horman cc: Jiayuan Chen cc: linux-afs@lists.infradead.org cc: stable@kernel.org Reviewed-by: Jeffrey Altman Tested-by: Marc Dionne Link: https://patch.msgid.link/20260515230516.2718212-4-dhowells@redhat.com Signed-off-by: Jakub Kicinski --- net/rxrpc/ar-internal.h | 7 ++-- net/rxrpc/conn_event.c | 32 +++++++---------- net/rxrpc/insecure.c | 5 +-- net/rxrpc/rxgk.c | 96 ++++++++++++++++--------------------------------- net/rxrpc/rxgk_app.c | 46 ++++++++++-------------- net/rxrpc/rxgk_common.h | 92 ++--------------------------------------------- net/rxrpc/rxkad.c | 29 ++++++--------- 7 files changed, 82 insertions(+), 225 deletions(-) (limited to 'net') diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 783367eea798..98f2165159d7 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -307,15 +307,16 @@ struct rxrpc_security { struct sk_buff *challenge); /* verify a response */ - int (*verify_response)(struct rxrpc_connection *, - struct sk_buff *); + int (*verify_response)(struct rxrpc_connection *conn, + struct sk_buff *response_skb, + void *response, unsigned int len); /* clear connection security */ void (*clear)(struct rxrpc_connection *); /* Default ticket -> key decoder */ int (*default_decode_ticket)(struct rxrpc_connection *conn, struct sk_buff *skb, - unsigned int ticket_offset, unsigned int ticket_len, + void *ticket, unsigned int ticket_len, struct key **_key); }; diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c index 442414d90ba1..c96ca615b787 100644 --- a/net/rxrpc/conn_event.c +++ b/net/rxrpc/conn_event.c @@ -243,28 +243,22 @@ static void rxrpc_call_is_secure(struct rxrpc_call *call) static int rxrpc_verify_response(struct rxrpc_connection *conn, struct sk_buff *skb) { + unsigned int len = skb->len - sizeof(struct rxrpc_wire_header); + void *buffer; int ret; - if (skb_cloned(skb) || skb_has_frag_list(skb) || - skb_has_shared_frag(skb)) { - /* Copy the packet if shared so that we can do in-place - * decryption. - */ - struct sk_buff *nskb = skb_copy(skb, GFP_NOFS); - - if (nskb) { - rxrpc_new_skb(nskb, rxrpc_skb_new_unshared); - ret = conn->security->verify_response(conn, nskb); - rxrpc_free_skb(nskb, rxrpc_skb_put_response_copy); - } else { - /* OOM - Drop the packet. */ - rxrpc_see_skb(skb, rxrpc_skb_see_unshare_nomem); - ret = -ENOMEM; - } - } else { - ret = conn->security->verify_response(conn, skb); - } + buffer = kmalloc(len, GFP_NOFS); + if (!buffer) + return -ENOMEM; + + ret = skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), buffer, len); + if (ret < 0) + goto out; + + ret = conn->security->verify_response(conn, skb, buffer, len); +out: + kfree(buffer); return ret; } diff --git a/net/rxrpc/insecure.c b/net/rxrpc/insecure.c index 7a26c6097d03..0b39046bdc61 100644 --- a/net/rxrpc/insecure.c +++ b/net/rxrpc/insecure.c @@ -54,9 +54,10 @@ static int none_sendmsg_respond_to_challenge(struct sk_buff *challenge, } static int none_verify_response(struct rxrpc_connection *conn, - struct sk_buff *skb) + struct sk_buff *response_skb, + void *response, unsigned int len) { - return rxrpc_abort_conn(conn, skb, RX_PROTOCOL_ERROR, -EPROTO, + return rxrpc_abort_conn(conn, response_skb, RX_PROTOCOL_ERROR, -EPROTO, rxrpc_eproto_rxnull_response); } diff --git a/net/rxrpc/rxgk.c b/net/rxrpc/rxgk.c index f81703ee7ac3..a1ee102abae1 100644 --- a/net/rxrpc/rxgk.c +++ b/net/rxrpc/rxgk.c @@ -1084,11 +1084,12 @@ static int rxgk_sendmsg_respond_to_challenge(struct sk_buff *challenge, * unsigned int call_numbers<>; * }; */ -static int rxgk_do_verify_authenticator(struct rxrpc_connection *conn, - const struct krb5_enctype *krb5, - struct sk_buff *skb, - __be32 *p, __be32 *end) +static int rxgk_verify_authenticator(struct rxrpc_connection *conn, + const struct krb5_enctype *krb5, + struct sk_buff *skb, + void *auth, unsigned int auth_len) { + __be32 *p = auth, *end = auth + auth_len; u32 app_len, call_count, level, epoch, cid, i; _enter(""); @@ -1151,37 +1152,6 @@ static int rxgk_do_verify_authenticator(struct rxrpc_connection *conn, return 0; } -/* - * Extract the authenticator and verify it. - */ -static int rxgk_verify_authenticator(struct rxrpc_connection *conn, - const struct krb5_enctype *krb5, - struct sk_buff *skb, - unsigned int auth_offset, unsigned int auth_len) -{ - void *auth; - __be32 *p; - int ret; - - auth = kmalloc(auth_len, GFP_NOFS); - if (!auth) - return -ENOMEM; - - ret = skb_copy_bits(skb, auth_offset, auth, auth_len); - if (ret < 0) { - ret = rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EPROTO, - rxgk_abort_resp_short_auth); - goto error; - } - - p = auth; - ret = rxgk_do_verify_authenticator(conn, krb5, skb, p, - p + auth_len / sizeof(*p)); -error: - kfree(auth); - return ret; -} - /* * Verify a response. * @@ -1192,49 +1162,45 @@ error: * }; */ static int rxgk_verify_response(struct rxrpc_connection *conn, - struct sk_buff *skb) + struct sk_buff *skb, + void *buffer, unsigned int len) { const struct krb5_enctype *krb5; struct rxrpc_key_token *token; struct rxrpc_skb_priv *sp = rxrpc_skb(skb); - struct rxgk_response rhdr; + struct rxgk_response *rhdr; struct rxgk_context *gk; struct key *key = NULL; - unsigned int offset = sizeof(struct rxrpc_wire_header); - unsigned int len = skb->len - sizeof(struct rxrpc_wire_header); - unsigned int token_offset, token_len; - unsigned int auth_offset, auth_len; + unsigned int resp_token_len, auth_len; + void *resp_token, *auth; __be32 xauth_len; int ret, ec; _enter("{%d}", conn->debug_id); /* Parse the RXGK_Response object */ - if (sizeof(rhdr) + sizeof(__be32) > len) - goto short_packet; - - if (skb_copy_bits(skb, offset, &rhdr, sizeof(rhdr)) < 0) + if (len < sizeof(*rhdr) + sizeof(__be32)) goto short_packet; - offset += sizeof(rhdr); - len -= sizeof(rhdr); - - token_offset = offset; - token_len = ntohl(rhdr.token_len); - if (token_len > len || - xdr_round_up(token_len) + sizeof(__be32) > len) + rhdr = buffer; + buffer += sizeof(*rhdr); + len -= sizeof(*rhdr); + + resp_token = buffer; + resp_token_len = ntohl(rhdr->token_len); + if (resp_token_len > len || + xdr_round_up(resp_token_len) + sizeof(__be32) > len) goto short_packet; - trace_rxrpc_rx_response(conn, sp->hdr.serial, 0, sp->hdr.cksum, token_len); + trace_rxrpc_rx_response(conn, sp->hdr.serial, 0, sp->hdr.cksum, resp_token_len); - offset += xdr_round_up(token_len); - len -= xdr_round_up(token_len); + buffer += xdr_round_up(resp_token_len); + len -= xdr_round_up(resp_token_len); - if (skb_copy_bits(skb, offset, &xauth_len, sizeof(xauth_len)) < 0) - goto short_packet; - offset += sizeof(xauth_len); + xauth_len = *(__be32 *)buffer; + buffer += sizeof(xauth_len); len -= sizeof(xauth_len); - auth_offset = offset; + auth = buffer; auth_len = ntohl(xauth_len); if (auth_len > len) goto short_packet; @@ -1249,7 +1215,7 @@ static int rxgk_verify_response(struct rxrpc_connection *conn, * to the app to deal with - which might mean a round trip to * userspace. */ - ret = rxgk_extract_token(conn, skb, token_offset, token_len, &key); + ret = rxgk_extract_token(conn, skb, resp_token, resp_token_len, &key); if (ret < 0) goto out; @@ -1263,7 +1229,7 @@ static int rxgk_verify_response(struct rxrpc_connection *conn, */ token = key->payload.data[0]; conn->security_level = token->rxgk->level; - conn->rxgk.start_time = __be64_to_cpu(rhdr.start_time); + conn->rxgk.start_time = __be64_to_cpu(rhdr->start_time); gk = rxgk_generate_transport_key(conn, token->rxgk, sp->hdr.cksum, GFP_NOFS); if (IS_ERR(gk)) { @@ -1273,18 +1239,18 @@ static int rxgk_verify_response(struct rxrpc_connection *conn, krb5 = gk->krb5; - trace_rxrpc_rx_response(conn, sp->hdr.serial, krb5->etype, sp->hdr.cksum, token_len); + trace_rxrpc_rx_response(conn, sp->hdr.serial, krb5->etype, sp->hdr.cksum, + resp_token_len); /* Decrypt, parse and verify the authenticator. */ - ret = rxgk_decrypt_skb(krb5, gk->resp_enc, skb, - &auth_offset, &auth_len, &ec); + ret = rxgk_decrypt(krb5, gk->resp_enc, &auth, &auth_len, &ec); if (ret < 0) { rxrpc_abort_conn(conn, skb, RXGK_SEALEDINCON, ret, rxgk_abort_resp_auth_dec); goto out_gk; } - ret = rxgk_verify_authenticator(conn, krb5, skb, auth_offset, auth_len); + ret = rxgk_verify_authenticator(conn, krb5, skb, auth, auth_len); if (ret < 0) goto out_gk; diff --git a/net/rxrpc/rxgk_app.c b/net/rxrpc/rxgk_app.c index 0ef2a29eb695..200a30064fae 100644 --- a/net/rxrpc/rxgk_app.c +++ b/net/rxrpc/rxgk_app.c @@ -40,7 +40,7 @@ * }; */ int rxgk_yfs_decode_ticket(struct rxrpc_connection *conn, struct sk_buff *skb, - unsigned int ticket_offset, unsigned int ticket_len, + void *buffer, unsigned int ticket_len, struct key **_key) { struct rxrpc_key_token *token; @@ -49,7 +49,7 @@ int rxgk_yfs_decode_ticket(struct rxrpc_connection *conn, struct sk_buff *skb, size_t pre_ticket_len, payload_len; unsigned int klen, enctype; void *payload, *ticket; - __be32 *t, *p, *q, tmp[2]; + __be32 *t, *p, *q, *tmp; int ret; _enter(""); @@ -59,10 +59,7 @@ int rxgk_yfs_decode_ticket(struct rxrpc_connection *conn, struct sk_buff *skb, rxgk_abort_resp_short_yfs_tkt); /* Get the session key length */ - ret = skb_copy_bits(skb, ticket_offset, tmp, sizeof(tmp)); - if (ret < 0) - return rxrpc_abort_conn(conn, skb, RXGK_INCONSISTENCY, -EPROTO, - rxgk_abort_resp_short_yfs_klen); + tmp = buffer; enctype = ntohl(tmp[0]); klen = ntohl(tmp[1]); @@ -84,12 +81,7 @@ int rxgk_yfs_decode_ticket(struct rxrpc_connection *conn, struct sk_buff *skb, * it. */ ticket = payload + pre_ticket_len; - ret = skb_copy_bits(skb, ticket_offset, ticket, ticket_len); - if (ret < 0) { - ret = rxrpc_abort_conn(conn, skb, RXGK_INCONSISTENCY, -EPROTO, - rxgk_abort_resp_short_yfs_tkt); - goto error; - } + memcpy(ticket, buffer, ticket_len); /* Fill out the form header. */ p = payload; @@ -131,7 +123,7 @@ int rxgk_yfs_decode_ticket(struct rxrpc_connection *conn, struct sk_buff *skb, goto error; } - /* Ticket read in with skb_copy_bits above */ + /* Ticket appended above. */ q += xdr_round_up(ticket_len) / 4; if (WARN_ON((unsigned long)q - (unsigned long)payload != payload_len)) { ret = -EIO; @@ -182,14 +174,15 @@ error: * [tools.ietf.org/html/draft-wilkinson-afs3-rxgk-afs-08 sec 6.1] */ int rxgk_extract_token(struct rxrpc_connection *conn, struct sk_buff *skb, - unsigned int token_offset, unsigned int token_len, + void *token, unsigned int token_len, struct key **_key) { const struct krb5_enctype *krb5; const struct krb5_buffer *server_secret; struct crypto_aead *token_enc = NULL; struct key *server_key; - unsigned int ticket_offset, ticket_len; + unsigned int ticket_len; + void *ticket; u32 kvno, enctype; int ret, ec = 0; @@ -197,24 +190,23 @@ int rxgk_extract_token(struct rxrpc_connection *conn, struct sk_buff *skb, __be32 kvno; __be32 enctype; __be32 token_len; - } container; + } *container; - if (token_len < sizeof(container)) + if (token_len < sizeof(*container)) goto short_packet; /* Decode the RXGK_TokenContainer object. This tells us which server * key we should be using. We can then fetch the key, get the secret * and set up the crypto to extract the token. */ - if (skb_copy_bits(skb, token_offset, &container, sizeof(container)) < 0) - goto short_packet; + container = token; + token += sizeof(*container); - kvno = ntohl(container.kvno); - enctype = ntohl(container.enctype); - ticket_len = ntohl(container.token_len); - ticket_offset = token_offset + sizeof(container); + kvno = ntohl(container->kvno); + enctype = ntohl(container->enctype); + ticket_len = ntohl(container->token_len); - if (ticket_len > xdr_round_down(token_len - sizeof(container))) + if (ticket_len > xdr_round_down(token_len - sizeof(*container))) goto short_packet; _debug("KVNO %u", kvno); @@ -237,8 +229,8 @@ int rxgk_extract_token(struct rxrpc_connection *conn, struct sk_buff *skb, * gain access to K0, from which we can derive the transport key and * thence decode the authenticator. */ - ret = rxgk_decrypt_skb(krb5, token_enc, skb, - &ticket_offset, &ticket_len, &ec); + ticket = token; + ret = rxgk_decrypt(krb5, token_enc, &ticket, &ticket_len, &ec); crypto_free_aead(token_enc); token_enc = NULL; if (ret < 0) { @@ -248,7 +240,7 @@ int rxgk_extract_token(struct rxrpc_connection *conn, struct sk_buff *skb, return ret; } - ret = conn->security->default_decode_ticket(conn, skb, ticket_offset, + ret = conn->security->default_decode_ticket(conn, skb, ticket, ticket_len, _key); if (ret < 0) goto cant_get_token; diff --git a/net/rxrpc/rxgk_common.h b/net/rxrpc/rxgk_common.h index 112b5366ce11..3deed5863f5a 100644 --- a/net/rxrpc/rxgk_common.h +++ b/net/rxrpc/rxgk_common.h @@ -41,10 +41,10 @@ struct rxgk_context { * rxgk_app.c */ int rxgk_yfs_decode_ticket(struct rxrpc_connection *conn, struct sk_buff *skb, - unsigned int ticket_offset, unsigned int ticket_len, + void *ticket, unsigned int ticket_len, struct key **_key); int rxgk_extract_token(struct rxrpc_connection *conn, struct sk_buff *skb, - unsigned int token_offset, unsigned int token_len, + void *token, unsigned int token_len, struct key **_key); /* @@ -61,50 +61,6 @@ int rxgk_set_up_token_cipher(const struct krb5_buffer *server_key, const struct krb5_enctype **_krb5, gfp_t gfp); -/* - * Apply decryption and checksumming functions to part of an skbuff. The - * offset and length are updated to reflect the actual content of the encrypted - * region. - */ -static inline -int rxgk_decrypt_skb(const struct krb5_enctype *krb5, - struct crypto_aead *aead, - struct sk_buff *skb, - unsigned int *_offset, unsigned int *_len, - int *_error_code) -{ - struct scatterlist sg[16]; - size_t offset = 0, len = *_len; - int nr_sg, ret; - - sg_init_table(sg, ARRAY_SIZE(sg)); - nr_sg = skb_to_sgvec(skb, sg, *_offset, len); - if (unlikely(nr_sg < 0)) - return nr_sg; - - ret = crypto_krb5_decrypt(krb5, aead, sg, nr_sg, - &offset, &len); - switch (ret) { - case 0: - *_offset += offset; - *_len = len; - break; - case -EBADMSG: /* Checksum mismatch. */ - case -EPROTO: - *_error_code = RXGK_SEALEDINCON; - break; - case -EMSGSIZE: - *_error_code = RXGK_PACKETSHORT; - break; - case -ENOPKG: /* Would prefer RXGK_BADETYPE, but not available for YFS. */ - default: - *_error_code = RXGK_INCONSISTENCY; - break; - } - - return ret; -} - /* * Apply decryption and checksumming functions a flat data buffer. The data * point and length are updated to reflect the actual content of the encrypted @@ -148,50 +104,6 @@ static inline int rxgk_decrypt(const struct krb5_enctype *krb5, return ret; } -/* - * Check the MIC on a region of an skbuff. The offset and length are updated - * to reflect the actual content of the secure region. - */ -static inline -int rxgk_verify_mic_skb(const struct krb5_enctype *krb5, - struct crypto_shash *shash, - const struct krb5_buffer *metadata, - struct sk_buff *skb, - unsigned int *_offset, unsigned int *_len, - u32 *_error_code) -{ - struct scatterlist sg[16]; - size_t offset = 0, len = *_len; - int nr_sg, ret; - - sg_init_table(sg, ARRAY_SIZE(sg)); - nr_sg = skb_to_sgvec(skb, sg, *_offset, len); - if (unlikely(nr_sg < 0)) - return nr_sg; - - ret = crypto_krb5_verify_mic(krb5, shash, metadata, sg, nr_sg, - &offset, &len); - switch (ret) { - case 0: - *_offset += offset; - *_len = len; - break; - case -EBADMSG: /* Checksum mismatch */ - case -EPROTO: - *_error_code = RXGK_SEALEDINCON; - break; - case -EMSGSIZE: - *_error_code = RXGK_PACKETSHORT; - break; - case -ENOPKG: /* Would prefer RXGK_BADETYPE, but not available for YFS. */ - default: - *_error_code = RXGK_INCONSISTENCY; - break; - } - - return ret; -} - /* * Check the MIC on a flat buffer. The data pointer and length are updated to * reflect the actual content of the secure region. diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c index 075936337836..6fbd883401ac 100644 --- a/net/rxrpc/rxkad.c +++ b/net/rxrpc/rxkad.c @@ -963,7 +963,6 @@ static int rxkad_decrypt_ticket(struct rxrpc_connection *conn, *_expiry = 0; ASSERT(server_key->payload.data[0] != NULL); - ASSERTCMP((unsigned long) ticket & 7UL, ==, 0); memcpy(&iv, &server_key->payload.data[2], sizeof(iv)); @@ -1112,14 +1111,15 @@ unlock: * verify a response */ static int rxkad_verify_response(struct rxrpc_connection *conn, - struct sk_buff *skb) + struct sk_buff *skb, + void *buffer, unsigned int len) { struct rxkad_response *response; struct rxrpc_skb_priv *sp = rxrpc_skb(skb); struct rxrpc_crypt session_key; struct key *server_key; time64_t expiry; - void *ticket = NULL; + void *ticket; u32 version, kvno, ticket_len, level; __be32 csum; int ret, i; @@ -1142,13 +1142,8 @@ static int rxkad_verify_response(struct rxrpc_connection *conn, } } - ret = -ENOMEM; - response = kzalloc_obj(struct rxkad_response, GFP_NOFS); - if (!response) - goto error; - - if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), - response, sizeof(*response)) < 0) { + response = buffer; + if (len < sizeof(*response)) { ret = rxrpc_abort_conn(conn, skb, RXKADPACKETSHORT, -EPROTO, rxkad_abort_resp_short); goto error; @@ -1160,6 +1155,9 @@ static int rxkad_verify_response(struct rxrpc_connection *conn, trace_rxrpc_rx_response(conn, sp->hdr.serial, version, kvno, ticket_len); + buffer += sizeof(*response); + len -= sizeof(*response); + if (version != RXKAD_VERSION) { ret = rxrpc_abort_conn(conn, skb, RXKADINCONSISTENCY, -EPROTO, rxkad_abort_resp_version); @@ -1179,13 +1177,8 @@ static int rxkad_verify_response(struct rxrpc_connection *conn, } /* extract the kerberos ticket and decrypt and decode it */ - ret = -ENOMEM; - ticket = kmalloc(ticket_len, GFP_NOFS); - if (!ticket) - goto error; - - if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header) + sizeof(*response), - ticket, ticket_len) < 0) { + ticket = buffer; + if (ticket_len > len) { ret = rxrpc_abort_conn(conn, skb, RXKADPACKETSHORT, -EPROTO, rxkad_abort_resp_short_tkt); goto error; @@ -1265,8 +1258,6 @@ static int rxkad_verify_response(struct rxrpc_connection *conn, ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno); error: - kfree(ticket); - kfree(response); key_put(server_key); _leave(" = %d", ret); return ret; -- cgit v1.2.3 From ddf8029623a1af20e984c040e89ff918158397ab Mon Sep 17 00:00:00 2001 From: Xingwang Xiang Date: Sun, 17 May 2026 23:56:26 +0900 Subject: bpf, skmsg: fix verdict sk_data_ready racing with ktls rx sk_psock_strp_data_ready() already checks tls_sw_has_ctx_rx() and defers to psock->saved_data_ready when a TLS RX context is present, avoiding a conflict with the TLS strparser's ownership of the receive queue (commit e91de6afa81c, "bpf: Fix running sk_skb program types with ktls"). sk_psock_verdict_data_ready() has no equivalent guard. When a socket is inserted into a sockmap (BPF_SK_SKB_VERDICT) before TLS RX is configured, tls_sw_strparser_arm() saves sk_psock_verdict_data_ready as rx_ctx->saved_data_ready. On data arrival: tls_data_ready -> tls_strp_data_ready -> tls_rx_msg_ready -> saved_data_ready() = sk_psock_verdict_data_ready() -> tcp_read_skb() drains sk_receive_queue via __skb_unlink() without calling tcp_eat_skb(), so copied_seq is not advanced. tls_strp_msg_load() then finds tcp_inq() >= full_len (stale), calls tcp_recv_skb() on the now-empty queue, hits WARN_ON_ONCE(!first), and returns with rx_ctx->strp.anchor.frag_list pointing at a psock-owned (potentially freed) skb. tls_decrypt_sg() subsequently walks that frag_list: use-after-free. Apply the same fix as sk_psock_strp_data_ready(): if a TLS RX context is present, call psock->saved_data_ready (sock_def_readable) to wake recv() waiters and return immediately, leaving the receive queue untouched. TLS retains sole ownership of the queue and decrypts the record normally through tls_sw_recvmsg(). Fixes: ef5659280eb1 ("bpf, sockmap: Allow skipping sk_skb parser program") Signed-off-by: Xingwang Xiang Link: https://patch.msgid.link/20260517145630.20521-2-v3rdant.xiang@gmail.com Signed-off-by: Jakub Kicinski --- net/core/skmsg.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 6187a83bd741..e1850caf1a71 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -1268,12 +1268,19 @@ out: static void sk_psock_verdict_data_ready(struct sock *sk) { const struct proto_ops *ops = NULL; + struct sk_psock *psock; struct socket *sock; int copied; trace_sk_data_ready(sk); rcu_read_lock(); + psock = sk_psock(sk); + if (psock && tls_sw_has_ctx_rx(sk)) { + psock->saved_data_ready(sk); + rcu_read_unlock(); + return; + } sock = READ_ONCE(sk->sk_socket); if (likely(sock)) ops = READ_ONCE(sock->ops); @@ -1283,8 +1290,6 @@ static void sk_psock_verdict_data_ready(struct sock *sk) copied = ops->read_skb(sk, sk_psock_verdict_recv); if (copied >= 0) { - struct sk_psock *psock; - rcu_read_lock(); psock = sk_psock(sk); if (psock) -- cgit v1.2.3 From 4eb82ba543421e9e38cc14e4e82058b78850df50 Mon Sep 17 00:00:00 2001 From: David Carlier Date: Tue, 19 May 2026 21:35:30 +0100 Subject: net: devmem: reject dma-buf bind with non-page-aligned size or SG length net_devmem_bind_dmabuf() trusts dmabuf->size and sg_dma_len() to be PAGE_SIZE multiples without checking: - tx_vec is sized dmabuf->size / PAGE_SIZE, and net_devmem_get_niov_at() only bounds-checks virt_addr < dmabuf->size before indexing tx_vec[virt_addr / PAGE_SIZE]. With size = N*PAGE_SIZE + r (1 <= r < PAGE_SIZE), sendmsg() at iov_base = N*PAGE_SIZE passes the bound check and reads tx_vec[N] -- one past. - owner->area.num_niovs = len / PAGE_SIZE while gen_pool_add_owner() covers the full byte len, so a non-page-multiple non-final sg desyncs num_niovs from the gen_pool region for every later sg, on both RX and TX. dma-buf does not require page-aligned sizes, so the bind path has to enforce what its own indexing assumes. Reject both with -EINVAL. The size check is TX-only (only tx_vec is sized off dmabuf->size); the SG-length check covers both directions. Fixes: bd61848900bf ("net: devmem: Implement TX path") Cc: stable@vger.kernel.org Signed-off-by: David Carlier Reviewed-by: Bobby Eshleman Acked-by: Stanislav Fomichev Reviewed-by: Mina Almasry Link: https://patch.msgid.link/20260519203530.66310-1-devnexen@gmail.com Signed-off-by: Jakub Kicinski --- net/core/devmem.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'net') diff --git a/net/core/devmem.c b/net/core/devmem.c index 468344739db2..4f71de44c0fb 100644 --- a/net/core/devmem.c +++ b/net/core/devmem.c @@ -241,6 +241,11 @@ net_devmem_bind_dmabuf(struct net_device *dev, } if (direction == DMA_TO_DEVICE) { + if (!IS_ALIGNED(dmabuf->size, PAGE_SIZE)) { + err = -EINVAL; + NL_SET_ERR_MSG(extack, "TX dma-buf size must be a multiple of PAGE_SIZE"); + goto err_unmap; + } binding->tx_vec = kvmalloc_objs(struct net_iov *, dmabuf->size / PAGE_SIZE); if (!binding->tx_vec) { @@ -267,6 +272,12 @@ net_devmem_bind_dmabuf(struct net_device *dev, size_t len = sg_dma_len(sg); struct net_iov *niov; + if (!IS_ALIGNED(len, PAGE_SIZE)) { + err = -EINVAL; + NL_SET_ERR_MSG(extack, "dma-buf SG length must be PAGE_SIZE aligned"); + goto err_free_chunks; + } + owner = kzalloc_node(sizeof(*owner), GFP_KERNEL, dev_to_node(&dev->dev)); if (!owner) { -- cgit v1.2.3 From 7eb72c1e3984150c45f77aa4299f7c2598a68e9b Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 19 May 2026 20:08:36 +0000 Subject: ipv4: icmp: reject broadcast/multicast routes syzbot was able to trigger ip_rt_bug() in a loop, using an IPv4 packet with a crafted IPOPT_SSRR option: options: ipv4_options { options: array[ipv4_option] { union ipv4_option { ssrr: ipv4_option_route[IPOPT_SSRR] { type: const = 0x89 (1 bytes) length: len = 0x7 (1 bytes) pointer: int8 = 0xa2 (1 bytes) data: array[ipv4_addr] { union ipv4_addr { broadcast: const = 0xffffffff (4 bytes) } } } } Change __icmp_send() to not send ICMP to broadcast/multicast destinations. Fixes: c378a9c019cf ("ipv4: Give backtrace in ip_rt_bug().") Reported-by: syzbot+c13a57c2639c2c0d03a6@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a0cc169.170a0220.1f6c2d.0004.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://patch.msgid.link/20260519200836.4141061-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/ipv4/icmp.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net') diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 7eeff658b467..23e921d313b3 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -961,6 +961,9 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, if (IS_ERR(rt)) goto out_unlock; + if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) + goto ende; + /* peer icmp_ratelimit */ if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code, apply_ratelimit)) goto ende; -- cgit v1.2.3 From e4bdef4d320b2fe73b8ebfc0cc0507fa9dc4a3b7 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 19 May 2026 19:32:48 +0000 Subject: ipv4: use WARN_ON_ONCE() in ip_rt_bug() It turns out ip_rt_bug() can be called more than expected. syzbot will still panic (because of panic_on_warn=1), but non debug kernels will no longer die while repeating stack traces on the console. Fixes: c378a9c019cf ("ipv4: Give backtrace in ip_rt_bug().") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Jiayuan Chen Link: https://patch.msgid.link/20260519193248.4018872-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/ipv4/route.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/ipv4/route.c b/net/ipv4/route.c index bc1296f0ea69..3d62d45d84bd 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1272,7 +1272,7 @@ static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, skb->dev ? skb->dev->name : "?"); kfree_skb(skb); - WARN_ON(1); + WARN_ON_ONCE(1); return 0; } -- cgit v1.2.3 From 99e22ddf4edb63dc8382bc028af928056d3450cf Mon Sep 17 00:00:00 2001 From: Minh Nguyen Date: Tue, 19 May 2026 17:23:10 +0700 Subject: vsock/vmci: fix UAF when peer resets connection during handshake vmci_transport_recv_connecting_server() returned err = 0 for a peer RST in its default switch arm: err = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL; That made vmci_transport_recv_listen() skip vsock_remove_pending(), leaving the pending socket on the listener's pending_links with sk_state = TCP_CLOSE while destroy: still dropped the explicit reference taken before schedule_delayed_work(). One second later vsock_pending_work() observed is_pending=true and performed full cleanup: vsock_remove_pending() then the two trailing sock_put(sk) calls -- the first reached refcount 0 and __sk_freed the socket, and the second wrote into the freed object: BUG: KASAN: slab-use-after-free in refcount_warn_saturate Write of size 4 at addr ffff88800b1cac80 by task kworker Workqueue: events vsock_pending_work Treat peer RST like any other unexpected packet type (err = -EINVAL). All destroy: arms now return err < 0, so vmci_transport_recv_listen() removes pending from pending_links synchronously and vsock_pending_work() takes the is_pending=false / !rejected branch, dropping only its own work reference. This also closes the multi-packet race Sashiko reported on v2: pending is removed from the list before any subsequent packet can find it. The pre-existing sk_acceptq_removed() gap on the err < 0 path of vmci_transport_recv_listen() that Sashiko also noted is not introduced or changed by this patch. Tested on lts-6.12.79 with KASAN: 52/100 unpatched -> 0/100 patched. Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Cc: stable@vger.kernel.org Signed-off-by: Minh Nguyen Acked-by: Bryan Tan Link: https://patch.msgid.link/20260519102310.237181-1-minhnguyen.080505@gmail.com Signed-off-by: Jakub Kicinski --- net/vmw_vsock/vmci_transport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c index 4296ca1183f1..d2579380f51e 100644 --- a/net/vmw_vsock/vmci_transport.c +++ b/net/vmw_vsock/vmci_transport.c @@ -1164,7 +1164,7 @@ vmci_transport_recv_connecting_server(struct sock *listener, /* Close and cleanup the connection. */ vmci_transport_send_reset(pending, pkt); skerr = EPROTO; - err = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL; + err = -EINVAL; goto destroy; } -- cgit v1.2.3 From 1bbf0ced1d9db73ac7893c2187f3459288603e0d Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 19 May 2026 08:46:11 +0000 Subject: tcp: fix stale per-CPU tcp_tw_isn leak enabling ISN prediction Blamed commit moved the TIME_WAIT-derived ISN from the skb control block to a per-CPU variable, assuming the value would always be consumed by tcp_conn_request() for the same packet that wrote it. That assumption is violated by multiple drop paths between the producer (__this_cpu_write(tcp_tw_isn, isn) in tcp_v{4,6}_rcv()) and the consumer (tcp_conn_request()): - min_ttl / min_hopcount check - xfrm policy check - tcp_inbound_hash() MD5/AO mismatch - tcp_filter() eBPF/SO_ATTACH_FILTER drop - th->syn && th->fin discard in tcp_rcv_state_process() TCP_LISTEN - psp_sk_rx_policy_check() in tcp_v{4,6}_do_rcv() - tcp_checksum_complete() in tcp_v{4,6}_do_rcv() - tcp_v{4,6}_cookie_check() returning NULL When a packet is dropped on any of these paths, tcp_tw_isn is left set. The next SYN processed on the same CPU then consumes the non zero value in tcp_conn_request(), receiving a potentially predictable ISN. This patch moves back tcp_tw_isn to skb->cb[], getting rid of the per-cpu variable. Note that tcp_v{4,6}_fill_cb() do not set it. Very litle impact on overall code size/complexity: $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new add/remove: 0/0 grow/shrink: 2/1 up/down: 8/-15 (-7) Function old new delta tcp_v6_rcv 3038 3042 +4 tcp_v4_rcv 3035 3039 +4 tcp_conn_request 2938 2923 -15 Total: Before=24436060, After=24436053, chg -0.00% Fixes: 41eecbd712b7 ("tcp: replace TCP_SKB_CB(skb)->tcp_tw_isn with a per-cpu field") Reported-by: Chris Mason Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260519084611.2485277-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/ipv4/tcp.c | 3 --- net/ipv4/tcp_input.c | 15 ++++++--------- net/ipv4/tcp_ipv4.c | 3 ++- net/ipv6/tcp_ipv6.c | 3 ++- 4 files changed, 10 insertions(+), 14 deletions(-) (limited to 'net') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 432fa28e47d4..389a7cc17110 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -299,9 +299,6 @@ enum { DEFINE_PER_CPU(unsigned int, tcp_orphan_count); EXPORT_PER_CPU_SYMBOL_GPL(tcp_orphan_count); -DEFINE_PER_CPU(u32, tcp_tw_isn); -EXPORT_PER_CPU_SYMBOL_GPL(tcp_tw_isn); - long sysctl_tcp_mem[3] __read_mostly; DEFINE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index d5c9e65d9760..de9f68a9c0cf 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -7589,6 +7589,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, struct sock *sk, struct sk_buff *skb) { struct tcp_fastopen_cookie foc = { .len = -1 }; + u32 isn = TCP_SKB_CB(skb)->tcp_tw_isn; struct tcp_options_received tmp_opt; const struct tcp_sock *tp = tcp_sk(sk); struct net *net = sock_net(sk); @@ -7599,20 +7600,16 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, struct dst_entry *dst; struct flowi fl; u8 syncookies; - u32 isn; #ifdef CONFIG_TCP_AO const struct tcp_ao_hdr *aoh; #endif - isn = __this_cpu_read(tcp_tw_isn); - if (isn) { - /* TW buckets are converted to open requests without - * limitations, they conserve resources and peer is - * evidently real one. - */ - __this_cpu_write(tcp_tw_isn, 0); - } else { + /* If isn is non-zero, this SYN originally matched a TIME_WAIT socket. + * TW sockets are converted to open requests without limitations, + * we skip the queue limits and syncookie checks in the block below. + */ + if (!isn) { syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies); if (syncookies == 2 || inet_csk_reqsk_queue_is_full(sk)) { diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index c0526cc03980..fdc81150ff6c 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2198,6 +2198,7 @@ lookup: } } + isn = 0; process: if (static_branch_unlikely(&ip4_min_ttl)) { /* min_ttl can be changed concurrently from do_ip_setsockopt() */ @@ -2227,6 +2228,7 @@ process: th = (const struct tcphdr *)skb->data; iph = ip_hdr(skb); tcp_v4_fill_cb(skb, iph, th); + TCP_SKB_CB(skb)->tcp_tw_isn = isn; skb->dev = NULL; @@ -2313,7 +2315,6 @@ do_time_wait: sk = sk2; tcp_v4_restore_cb(skb); refcounted = false; - __this_cpu_write(tcp_tw_isn, isn); goto process; } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index d13d49bfef19..36d75fb50a70 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1839,6 +1839,7 @@ lookup: } } + isn = 0; process: if (static_branch_unlikely(&ip6_min_hopcount)) { /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */ @@ -1868,6 +1869,7 @@ process: th = (const struct tcphdr *)skb->data; hdr = ipv6_hdr(skb); tcp_v6_fill_cb(skb, hdr, th); + TCP_SKB_CB(skb)->tcp_tw_isn = isn; skb->dev = NULL; @@ -1956,7 +1958,6 @@ do_time_wait: sk = sk2; tcp_v6_restore_cb(skb); refcounted = false; - __this_cpu_write(tcp_tw_isn, isn); goto process; } -- cgit v1.2.3 From 48f6a5356a33dd78e7144ae1faef95ffc990aae0 Mon Sep 17 00:00:00 2001 From: Hyunwoo Kim Date: Sat, 16 May 2026 07:28:53 +0900 Subject: net: skbuff: propagate shared-frag marker through frag-transfer helpers Two frag-transfer helpers (__pskb_copy_fclone() and skb_shift()) fail to propagate the SKBFL_SHARED_FRAG bit in skb_shinfo()->flags when moving frags from source to destination. __pskb_copy_fclone() defers the rest of the shinfo metadata to skb_copy_header() after copying frag descriptors, but that helper only carries over gso_{size,segs, type} and never touches skb_shinfo()->flags; skb_shift() moves frag descriptors directly and leaves flags untouched. As a result, the destination skb keeps a reference to the same externally-owned or page-cache-backed pages while reporting skb_has_shared_frag() as false. The mismatch is harmful in any in-place writer that uses skb_has_shared_frag() to decide whether shared pages must be detoured through skb_cow_data(). ESP input is one such writer (esp4.c, esp6.c), and a single nft 'dup to ' rule -- or any other nf_dup_ipv4() / xt_TEE caller -- is enough to land a pskb_copy()'d skb in esp_input() with the marker stripped, letting an unprivileged user write into the page cache of a root-owned read-only file via authencesn-ESN stray writes. Set SKBFL_SHARED_FRAG on the destination whenever frag descriptors were actually moved from the source. skb_copy() and skb_copy_expand() share skb_copy_header() too but linearize all paged data into freshly allocated head storage and emerge with nr_frags == 0, so skb_has_shared_frag() returns false on its own; they need no change. The same omission exists in skb_gro_receive() and skb_gro_receive_list(). The former moves the incoming skb's frag descriptors into the accumulator's last sub-skb via two paths (a direct frag-move loop and the head_frag + memcpy path); the latter chains the incoming skb whole onto p's frag_list. Downstream skb_segment() reads only skb_shinfo(p)->flags, and skb_segment_list() reuses each sub-skb's shinfo as the nskb -- both p and lp must carry the marker. The same omission also exists in tcp_clone_payload(), which builds an MTU probe skb by moving frag descriptors from skbs on sk_write_queue into a freshly allocated nskb. The helper falls into the same family and warrants the same fix for consistency; no TCP TX-side in-place writer is currently known to reach a user page through this gap, but a future consumer depending on the marker would regress silently. The same omission exists in skb_segment(): the per-iteration flag merge takes only head_skb's flag, and the inner switch that rebinds frag_skb to list_skb on head_skb-frags exhaustion does not fold the new frag_skb's flag into nskb. Fold frag_skb's flag at both sites so segments drawing frags from frag_list members carry the marker. Fixes: cef401de7be8 ("net: fix possible wrong checksum generation") Fixes: f4c50a4034e6 ("xfrm: esp: avoid in-place decrypt on shared skb frags") Suggested-by: Sabrina Dubroca Suggested-by: Sultan Alsawaf Suggested-by: Ben Hutchings Suggested-by: Lin Ma Suggested-by: Jingguo Tan Suggested-by: Aaron Esau Cc: stable@vger.kernel.org Signed-off-by: Hyunwoo Kim Tested-by: Rajat Gupta Link: https://patch.msgid.link/ageeJfJHwgzmKXbh@v4bel Signed-off-by: Paolo Abeni --- net/core/gro.c | 4 ++++ net/core/skbuff.c | 9 ++++++++- net/ipv4/tcp_output.c | 1 + 3 files changed, 13 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/core/gro.c b/net/core/gro.c index 31d21de5b15a..9f8960789b2c 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -213,10 +213,12 @@ done: p->data_len += len; p->truesize += delta_truesize; p->len += len; + skb_shinfo(p)->flags |= skbinfo->flags & SKBFL_SHARED_FRAG; if (lp != p) { lp->data_len += len; lp->truesize += delta_truesize; lp->len += len; + skb_shinfo(lp)->flags |= skbinfo->flags & SKBFL_SHARED_FRAG; } NAPI_GRO_CB(skb)->same_flow = 1; return 0; @@ -244,6 +246,8 @@ int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb) p->truesize += skb->truesize; p->len += skb->len; + skb_shinfo(p)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; + NAPI_GRO_CB(skb)->same_flow = 1; return 0; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 9c4e8d331d6d..44ac121cfccb 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2248,6 +2248,7 @@ struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom, skb_frag_ref(skb, i); } skb_shinfo(n)->nr_frags = i; + skb_shinfo(n)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; } if (skb_has_frag_list(skb)) { @@ -4349,6 +4350,8 @@ onlymerged: tgt->ip_summed = CHECKSUM_PARTIAL; skb->ip_summed = CHECKSUM_PARTIAL; + skb_shinfo(tgt)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; + skb_len_add(skb, -shiftlen); skb_len_add(tgt, shiftlen); @@ -4959,7 +4962,8 @@ normal: skb_copy_from_linear_data_offset(head_skb, offset, skb_put(nskb, hsize), hsize); - skb_shinfo(nskb)->flags |= skb_shinfo(head_skb)->flags & + skb_shinfo(nskb)->flags |= (skb_shinfo(head_skb)->flags | + skb_shinfo(frag_skb)->flags) & SKBFL_SHARED_FRAG; if (skb_zerocopy_clone(nskb, frag_skb, GFP_ATOMIC)) @@ -4976,6 +4980,9 @@ normal: nfrags = skb_shinfo(list_skb)->nr_frags; frag = skb_shinfo(list_skb)->frags; frag_skb = list_skb; + + skb_shinfo(nskb)->flags |= skb_shinfo(frag_skb)->flags & SKBFL_SHARED_FRAG; + if (!skb_headlen(list_skb)) { BUG_ON(!nfrags); } else { diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f9d8755705f7..6e4bb411dc04 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2626,6 +2626,7 @@ static int tcp_clone_payload(struct sock *sk, struct sk_buff *to, todo = min_t(int, skb_frag_size(fragfrom), probe_size - len); len += todo; + skb_shinfo(to)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; if (lastfrag && skb_frag_page(fragfrom) == skb_frag_page(lastfrag) && skb_frag_off(fragfrom) == skb_frag_off(lastfrag) + -- cgit v1.2.3 From a4f0b001782b21663d10df983b4b208195bec66c Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Mon, 18 May 2026 11:06:55 +0200 Subject: vsock/virtio: reset connection on receiving queue overflow When there is no more space to queue an incoming packet, the packet is silently dropped. This causes data loss without any notification to either peer, since there is no retransmission. Under normal circumstances, this should never happen. However, it could happen if the other peer doesn't respect the credit, or if the skb overhead, which we recently began to take into account with commit 059b7dbd20a6 ("vsock/virtio: fix potential unbounded skb queue"), is too high. Fix this by resetting the connection and setting the local socket error to ENOBUFS when virtio_transport_recv_enqueue() can no longer queue a packet, so both peers are explicitly notified of the failure rather than silently losing data. Fixes: ae6fcfbf5f03 ("vsock/virtio: discard packets if credit is not respected") Cc: stable@vger.kernel.org Signed-off-by: Stefano Garzarella Link: https://patch.msgid.link/20260518090656.134588-2-sgarzare@redhat.com Signed-off-by: Paolo Abeni --- net/vmw_vsock/virtio_transport_common.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) (limited to 'net') diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 1e3409d28164..5028ff534888 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -1335,7 +1335,7 @@ destroy: return err; } -static void +static bool virtio_transport_recv_enqueue(struct vsock_sock *vsk, struct sk_buff *skb) { @@ -1350,10 +1350,8 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk, spin_lock_bh(&vvs->rx_lock); can_enqueue = virtio_transport_inc_rx_pkt(vvs, len); - if (!can_enqueue) { - free_pkt = true; + if (!can_enqueue) goto out; - } if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) vvs->msg_count++; @@ -1393,6 +1391,8 @@ out: spin_unlock_bh(&vvs->rx_lock); if (free_pkt) kfree_skb(skb); + + return can_enqueue; } static int @@ -1405,7 +1405,17 @@ virtio_transport_recv_connected(struct sock *sk, switch (le16_to_cpu(hdr->op)) { case VIRTIO_VSOCK_OP_RW: - virtio_transport_recv_enqueue(vsk, skb); + if (!virtio_transport_recv_enqueue(vsk, skb)) { + /* There is no more space to queue the packet, so let's + * close the connection; otherwise, we'll lose data. + */ + (void)virtio_transport_reset(vsk, skb); + virtio_transport_do_close(vsk, true); + sk->sk_err = ENOBUFS; + sk_error_report(sk); + vsock_remove_sock(vsk); + break; + } vsock_data_ready(sk); return err; case VIRTIO_VSOCK_OP_CREDIT_REQUEST: -- cgit v1.2.3 From c6087c5aaad6d1b8be1a1a641e0a422218ade911 Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Mon, 18 May 2026 11:06:56 +0200 Subject: vsock/virtio: fix skb overhead accounting to preserve full buf_alloc After commit 059b7dbd20a6 ("vsock/virtio: fix potential unbounded skb queue"), virtio_transport_inc_rx_pkt() subtracts per-skb overhead from buf_alloc when checking whether a new packet fits. This reduces the effective receive buffer below what the user configured via SO_VM_SOCKETS_BUFFER_SIZE, causing legitimate data packets to be silently dropped and applications that rely on the full buffer size to deadlock. Also, the reduced space is not communicated to the remote peer, so its credit calculation accounts more credit than the receiver will actually accept, causing data loss (there is no retransmission). With this approach we currently have failures in tools/testing/vsock/vsock_test.c. Test 18 sometimes fails, while test 22 always fails in this way: 18 - SOCK_STREAM MSG_ZEROCOPY...hash mismatch 22 - SOCK_STREAM virtio credit update + SO_RCVLOWAT...send failed: Resource temporarily unavailable Fix by allowing at most `buf_alloc * 2` as the total budget for payload plus skb overhead in virtio_transport_inc_rx_pkt(), similar to how SO_RCVBUF is doubled to reserve space for sk_buff metadata. This preserves the full buf_alloc for payload under normal operation, while still bounding the skb queue growth. With this patch, all tests in tools/testing/vsock/vsock_test.c are now passing again. Fixes: 059b7dbd20a6 ("vsock/virtio: fix potential unbounded skb queue") Cc: stable@vger.kernel.org Signed-off-by: Stefano Garzarella Link: https://patch.msgid.link/20260518090656.134588-3-sgarzare@redhat.com Signed-off-by: Paolo Abeni --- net/vmw_vsock/virtio_transport_common.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 5028ff534888..df3b418e0392 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -419,7 +419,14 @@ static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, { u64 skb_overhead = (skb_queue_len(&vvs->rx_queue) + 1) * SKB_TRUESIZE(0); - if (skb_overhead + vvs->buf_used + len > vvs->buf_alloc) + /* Allow at most buf_alloc * 2 total budget (payload + overhead), + * similar to how SO_RCVBUF is doubled to reserve space for sk_buff + * metadata. Check payload against buf_alloc to be sure the other + * peer is respecting the credit, and sk_buff overhead to bound + * queue growth. + */ + if ((u64)vvs->buf_used + len > vvs->buf_alloc || + skb_overhead > vvs->buf_alloc) return false; vvs->rx_bytes += len; -- cgit v1.2.3 From dbc81608e3a653dea6cf403f20cae35468b8ab9c Mon Sep 17 00:00:00 2001 From: Zijing Yin Date: Tue, 19 May 2026 10:26:33 -0700 Subject: phonet/pep: disable BH around forwarded sk_receive_skb() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The networking receive path is usually run from softirq context, but protocols that take the socket lock may have packets stored in the backlog and processed later from process context. In that case release_sock() -> __release_sock() drops the slock with spin_unlock_bh() and then calls sk->sk_backlog_rcv() with bottom halves enabled. Typical sk_backlog_rcv handlers process the socket whose backlog is being drained, so the BH state at entry is irrelevant for the slocks they touch. pep_do_rcv() is different: when the inbound skb targets an existing PEP pipe, it forwards the skb to a different *child* socket via sk_receive_skb(). That helper takes the child slock with bh_lock_sock_nested(), which is just spin_lock_nested() and assumes BH is already off. The same child slock therefore ends up acquired with BH on (process path) and with BH off (softirq path): process context softirq context --------------- --------------- release_sock(listener) __netif_receive_skb() __release_sock() phonet_rcv() spin_unlock_bh() __sk_receive_skb(listener) [BH now ENABLED] [BH already disabled] sk_backlog_rcv: sk_backlog_rcv: pep_do_rcv() pep_do_rcv() sk_receive_skb(child) sk_receive_skb(child) bh_lock_sock_nested(child) bh_lock_sock_nested(child) => SOFTIRQ-ON-W => IN-SOFTIRQ-W Lockdep flags this as inconsistent lock state, and it can become a real self-deadlock if a softirq on the same CPU tries to receive to the same child socket while its slock is held in the BH-enabled path: WARNING: inconsistent lock state inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. (slock-AF_PHONET/1){+.?.}-{3:3}, at: __sk_receive_skb+0x1cf/0x900 __sk_receive_skb net/core/sock.c:563 sk_receive_skb include/net/sock.h:2022 [inline] pep_do_rcv net/phonet/pep.c:675 sk_backlog_rcv include/net/sock.h:1190 __release_sock net/core/sock.c:3216 release_sock net/core/sock.c:3815 pep_sock_accept net/phonet/pep.c:879 Wrap the forwarded sk_receive_skb() in local_bh_disable() / local_bh_enable() so the child slock is always acquired with BH off. local_bh_disable() nests safely on the softirq path. Discovered via in-house syzkaller fuzzing; the same root cause also on the linux-6.1.y syzbot dashboard as extid 44f0626dd6284f02663c. Reproduced under KASAN + LOCKDEP + PROVE_LOCKING, reproducer: https://pastebin.com/A3t8xzCR Fixes: 9641458d3ec4 ("Phonet: Pipe End Point for Phonet Pipes protocol") Link: https://syzkaller.appspot.com/bug?extid=44f0626dd6284f02663c Cc: stable@vger.kernel.org Signed-off-by: Zijing Yin Acked-by: Rémi Denis-Courmont Reported-by: syzbot+9f4a135646b66c509935@syzkaller.appspotmail.com Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260519172635.86304-1-yzjaurora@gmail.com Signed-off-by: Jakub Kicinski --- net/phonet/pep.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/phonet/pep.c b/net/phonet/pep.c index 4dbf0914df7d..706927139393 100644 --- a/net/phonet/pep.c +++ b/net/phonet/pep.c @@ -671,8 +671,23 @@ static int pep_do_rcv(struct sock *sk, struct sk_buff *skb) /* Look for an existing pipe handle */ sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle); - if (sknode) - return sk_receive_skb(sknode, skb, 1); + if (sknode) { + int rc; + + /* pep_do_rcv() runs from two contexts: from softirq via + * phonet_rcv() -> __sk_receive_skb() with BH disabled, + * and from process context via + * release_sock() -> __release_sock(), which drops + * the listener slock with spin_unlock_bh() before draining + * the backlog. The child pipe slock is taken below via + * bh_lock_sock_nested(), which does not itself disable BH, so + * disable BH here to keep both acquire contexts consistent. + */ + local_bh_disable(); + rc = sk_receive_skb(sknode, skb, 1); + local_bh_enable(); + return rc; + } switch (hdr->message_id) { case PNS_PEP_CONNECT_REQ: -- cgit v1.2.3 From 1341db322417266fb5845df81d28305b83a37324 Mon Sep 17 00:00:00 2001 From: Yuho Choi Date: Tue, 19 May 2026 23:03:28 -0400 Subject: ipv6: route: Unregister netdevice notifier on BPF init failure ip6_route_init() registers ip6_route_dev_notifier before registering the IPv6 route BPF iterator target. If bpf_iter_register() fails after the notifier has been registered, the error path currently jumps to out_register_late_subsys and unwinds the RTNL handlers and pernet route state without removing the notifier from the netdevice notifier chain. This leaves ip6_route_dev_notify() callable after the IPv6 route state it uses has been torn down. Add a separate unwind label for the BPF iterator failure path and unregister the netdevice notifier before continuing with the existing cleanup. Fixes: 138d0be35b14 ("net: bpf: Add netlink and ipv6_route bpf_iter targets") Signed-off-by: Yuho Choi Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260520030329.1061183-1-dbgh9129@gmail.com Signed-off-by: Jakub Kicinski --- net/ipv6/route.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/ipv6/route.c b/net/ipv6/route.c index e3d355d1fbd6..b106e5fef9cb 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -6933,7 +6933,7 @@ int __init ip6_route_init(void) #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) ret = bpf_iter_register(); if (ret) - goto out_register_late_subsys; + goto out_register_notifier; #endif for_each_possible_cpu(cpu) { @@ -6946,6 +6946,10 @@ int __init ip6_route_init(void) out: return ret; +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) +out_register_notifier: + unregister_netdevice_notifier(&ip6_route_dev_notifier); +#endif out_register_late_subsys: rtnl_unregister_all(PF_INET6); unregister_pernet_subsys(&ip6_route_net_late_ops); -- cgit v1.2.3 From c367b9082194d01cb38bdefac6e887ebf1ab017d Mon Sep 17 00:00:00 2001 From: Zhang Cen Date: Tue, 19 May 2026 18:46:47 +0800 Subject: netpoll: normalize skb->dev to the netpoll device __netpoll_send_skb() always transmits through np->dev and queues busy packets on np->dev->npinfo->txq, but it leaves skb->dev unchanged. Stacked callers such as DSA and macvlan can reach netpoll with skb->dev still naming the upper device while np->dev is the lower device that owns the netpoll state. If the skb has to be deferred, queue_process() later dequeues it from the lower device's txq but retries it through skb->dev. That can re-enter the upper ndo_start_xmit path on an already transformed skb, and if the upper device disappears before the lower txq drains the workqueue can dereference a stale skb->dev pointer. The buggy scenario involves two paths, with each column showing the order within that path: path A label: netpoll enqueue path path B label: upper-device teardown 1. Stacked xmit calls netpoll 1. Teardown unregisters the upper with lower np->dev and upper net_device while lower npinfo skb->dev. stays alive. 2. __netpoll_send_skb() uses 2. netdev_release() runs for the np->dev->npinfo as the txq upper net_device. owner. 3. Busy transmit queues the skb 3. The lower txq still owns the on that lower txq with upper deferred skb. skb->dev. 4. queue_process() drains the 4. queue_process() dereferences lower txq and reads skb->dev. that stale upper skb->dev. Normalize skb->dev to np->dev after loading np->dev from the netpoll instance, before either the direct transmit path or the fallback enqueue. This keeps the queued skb in the same device and txq domain as the netpoll state that owns it. KASAN report as below: KASAN slab-use-after-free in queue_process+0x7c/0x480 Workqueue: events queue_process The buggy address belongs to the object at ffff88810906c000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 168 bytes inside of freed 4096-byte region [ffff88810906c000, ffff88810906d000) Read of size 8 Call trace: dump_stack_lvl+0x73/0xb0 (?:?) print_report+0xd1/0x620 (?:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x215/0x420 (?:?) kasan_complete_mode_report_info+0x64/0x200 (?:?) kasan_report+0xf7/0x130 (?:?) queue_process+0x7c/0x480 (net/core/netpoll.c:88) kasan_check_range+0x10c/0x1c0 (?:?) __kasan_check_read+0x15/0x20 (?:?) process_one_work+0x8b7/0x1af0 (kernel/workqueue.c:3200) assign_work+0x170/0x3f0 (?:?) worker_thread+0x574/0xf10 (?:?) _raw_spin_unlock_irqrestore+0x4b/0x60 (?:?) trace_hardirqs_on+0x2a/0x180 (?:?) kthread+0x2fc/0x3f0 (?:?) ret_from_fork+0x58b/0x830 (?:?) __switch_to+0x58e/0xe90 (?:?) __switch_to_asm+0x39/0x70 (?:?) ret_from_fork_asm+0x1a/0x30 (?:?) Freed by task stack: kasan_save_stack+0x3d/0x60 (?:?) kasan_save_track+0x18/0x40 (?:?) kasan_save_free_info+0x3f/0x60 (?:?) __kasan_slab_free+0x48/0x70 (?:?) kfree+0x20e/0x4e0 (?:?) kvfree+0x31/0x40 (?:?) netdev_release+0x71/0x90 (net/core/net-sysfs.c:2227) device_release+0xd2/0x250 (?:?) kobject_put+0x181/0x4c0 (lib/kobject.c:730) netdev_run_todo+0x700/0x1000 (net/core/dev.c:11666) rtnl_dellink+0x396/0xc00 (net/core/rtnetlink.c:3558) rtnetlink_rcv_msg+0x740/0xc20 (net/core/rtnetlink.c:6897) netlink_rcv_skb+0x147/0x3a0 (?:?) rtnetlink_rcv+0x19/0x20 (net/core/rtnetlink.c:7021) netlink_unicast+0x4d1/0x830 (net/netlink/af_netlink.c:1327) netlink_sendmsg+0x840/0xe10 (net/netlink/af_netlink.c:1812) ____sys_sendmsg+0x8a7/0xb50 (?:?) ___sys_sendmsg+0x104/0x190 (?:?) __sys_sendmsg+0x135/0x1d0 (?:?) __x64_sys_sendmsg+0x7b/0xc0 (?:?) x64_sys_call+0x205c/0x2130 (?:?) do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?) Fixes: 5de4a473bda4 ("netpoll queue cleanup") Signed-off-by: Zhang Cen Link: https://patch.msgid.link/20260519104647.3517990-1-rollkingzzc@gmail.com Signed-off-by: Jakub Kicinski --- net/core/netpoll.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net') diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 84faace50ac2..3f4a17fa5713 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -319,6 +319,8 @@ static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) lockdep_assert_irqs_disabled(); dev = np->dev; + /* npinfo->txq belongs to np->dev, so retries must stay bound to it. */ + skb->dev = dev; rcu_read_lock(); npinfo = rcu_dereference_bh(dev->npinfo); -- cgit v1.2.3 From e46e6bc97fb1f339730ff1ba74267fbf48e7a422 Mon Sep 17 00:00:00 2001 From: Justin Iurman Date: Wed, 20 May 2026 14:42:42 +0200 Subject: ipv6: ioam: refresh hdr pointer before ioam6_event() Reported by Sashiko: In ipv6_hop_ioam(), the hdr pointer is initialized to point into the skb's linear data buffer. Later, the code calls skb_ensure_writable(), which might reallocate the buffer: if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len)) goto drop; /* Trace pointer may have changed */ trace = (struct ioam6_trace_hdr *)(skb_network_header(skb) + optoff + sizeof(*hdr)); ioam6_fill_trace_data(skb, ns, trace, true); ioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev), GFP_ATOMIC, (void *)trace, hdr->opt_len - 2); If the skb is cloned or lacks sufficient linear headroom, skb_ensure_writable() will invoke pskb_expand_head(), which reallocates the skb's data buffer and frees the old one, invalidating pointers to it. While the code recalculates the trace pointer immediately after the call to skb_ensure_writable(), it fails to recalculate the hdr pointer. This patch fixes the above by recalculating the hdr pointer before passing hdr->opt_len to ioam6_event(), so that we avoid any UaF. Fixes: f655c78d6225 ("net: exthdrs: ioam6: send trace event") Cc: stable@vger.kernel.org Signed-off-by: Justin Iurman Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260520124242.32320-1-justin.iurman@gmail.com Signed-off-by: Jakub Kicinski --- net/ipv6/exthdrs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 47c5502a34a2..cf90f933ca1a 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -966,9 +966,9 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len)) goto drop; - /* Trace pointer may have changed */ - trace = (struct ioam6_trace_hdr *)(skb_network_header(skb) - + optoff + sizeof(*hdr)); + /* Trace and hdr pointers may have changed */ + hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); + trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); ioam6_fill_trace_data(skb, ns, trace, true); -- cgit v1.2.3 From 4db79a322db8c97f7b73b8a347395ef4d685eb40 Mon Sep 17 00:00:00 2001 From: Sabrina Dubroca Date: Wed, 20 May 2026 22:44:42 +0200 Subject: net: gro: don't merge zcopy skbs skb_gro_receive() can currently copy frags between the source and GRO skb, without checking the zerocopy status, and in particular the SKBFL_MANAGED_FRAG_REFS flag. When SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference on the pages in shinfo->frags. Appending those frags to another skb's frags without fixing up the page refcount can lead to UAF. When either the last skb in the GRO chain (the one we would append frags to) or the source skb is zerocopy, don't merge the skbs. Fixes: 753f1ca4e1e5 ("net: introduce managed frags infrastructure") Reported-by: Huzaifa Sidhpurwala Signed-off-by: Sabrina Dubroca Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/c3b7f906bbfcbdfd7b4fa9d6c18a438870df85be.1779307748.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski --- net/core/gro.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net') diff --git a/net/core/gro.c b/net/core/gro.c index 9f8960789b2c..a84753983467 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -109,6 +109,9 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) if (p->pp_recycle != skb->pp_recycle) return -ETOOMANYREFS; + if (skb_zcopy(p) || skb_zcopy(skb)) + return -ETOOMANYREFS; + if (unlikely(p->len + len >= netif_get_gro_max_size(p->dev, p) || NAPI_GRO_CB(skb)->flush)) return -E2BIG; -- cgit v1.2.3 From 979c017803c40829b03acd9e5236e354b7622360 Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Mon, 18 May 2026 14:34:47 -0400 Subject: l2tp: use list_del_rcu in l2tp_session_unhash An unprivileged local user can pin a host CPU indefinitely in l2tp_session_get_by_ifname() by issuing L2TP_CMD_SESSION_GET on L2TP_ATTR_IFNAME concurrently with L2TP_CMD_SESSION_CREATE and L2TP_CMD_SESSION_DELETE on the same tunnel. All three commands take GENL_UNS_ADMIN_PERM, so CAP_NET_ADMIN in the netns user namespace suffices; on any host that has l2tp_core loaded the trigger is reachable from a standard `unshare -Urn` sandbox. l2tp_session_unhash() removes a session from tunnel->session_list with list_del_init(), but that list is walked by l2tp_session_get_by_ifname() with list_for_each_entry_rcu() under rcu_read_lock_bh(). list_del_init() leaves the deleted entry's next/prev self-pointing; a reader that has loaded the entry and then advances pos->list.next reads &session->list, container_of()s back to the same session, and list_for_each_entry_rcu() never reaches the list head. The CPU stays in strcmp() inside the walker, with BH and preemption disabled, so RCU grace periods on the host stall behind it and the wedged thread cannot be killed (SIGKILL is delivered on syscall return). Use list_del_rcu() to match the existing list_add_rcu() in l2tp_session_register(); the deleted session remains visible to in-flight walkers with consistent next/prev pointers until kfree_rcu() in l2tp_session_free() releases it. tunnel->session_list has exactly one list_del_init() call site; the list_del_init (&session->clist) at l2tp_core.c:533 operates on the per-collision list, which is not walked under RCU. list_empty(&session->list) is not used anywhere in net/l2tp/ after the unhash point, so dropping the post-delete self-init is safe; the fix has no userspace-visible behavior change. Fixes: 89b768ec2dfef ("l2tp: use rcu list add/del when updating lists") Cc: stable@vger.kernel.org # 6.11+ Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/20260518183447.64078-1-michael.bommarito@gmail.com Signed-off-by: Jakub Kicinski --- net/l2tp/l2tp_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 157fc23ce4e1..1455f67e01dd 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1360,7 +1360,7 @@ static void l2tp_session_unhash(struct l2tp_session *session) spin_lock_bh(&pn->l2tp_session_idr_lock); /* Remove from the per-tunnel list */ - list_del_init(&session->list); + list_del_rcu(&session->list); /* Remove from per-net IDR */ if (tunnel->version == L2TP_HDR_VER_3) { -- cgit v1.2.3 From bdd39576bf50a50bdafe3da968fd271bc674a48f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 20 May 2026 11:42:07 +0000 Subject: net: bridge: prevent too big nested attributes in br_fill_linkxstats() After commit ff205bf8c554 ("netlink: add one debug check in nla_nest_end()") syzbot found that br_fill_linkxstats() can send corrupted netlink packets. Make sure the nested attribute size is bounded. Fixes: a60c090361ea ("bridge: netlink: export per-vlan stats") Reported-by: syzbot+a35f9259d08f907c06e6@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a0b0da3.050a0220.175f0c.0000.GAE@google.com/ Signed-off-by: Eric Dumazet Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260520114207.1394241-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/bridge/br_netlink.c | 10 ++++++++++ net/core/rtnetlink.c | 5 +++-- 2 files changed, 13 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c index 6fd5386a1d64..c04a4d0889ae 100644 --- a/net/bridge/br_netlink.c +++ b/net/bridge/br_netlink.c @@ -1824,6 +1824,7 @@ static int br_fill_linkxstats(struct sk_buff *skb, const struct net_device *dev, int *prividx, int attr) { + unsigned int limit = U16_MAX - nla_total_size(0); struct nlattr *nla __maybe_unused; struct net_bridge_port *p = NULL; struct net_bridge_vlan_group *vg; @@ -1841,6 +1842,7 @@ static int br_fill_linkxstats(struct sk_buff *skb, p = br_port_get_rtnl(dev); if (!p) return 0; + limit -= nla_total_size_64bit(sizeof(p->stp_xstats)); br = p->br; vg = nbp_vlan_group(p); break; @@ -1855,6 +1857,9 @@ static int br_fill_linkxstats(struct sk_buff *skb, if (vg) { u16 pvid; +#ifdef CONFIG_BRIDGE_IGMP_SNOOPING + limit -= nla_total_size_64bit(sizeof(struct br_mcast_stats)); +#endif pvid = br_get_pvid(vg); list_for_each_entry(v, &vg->vlan_list, vlist) { struct bridge_vlan_xstats vxi; @@ -1862,6 +1867,11 @@ static int br_fill_linkxstats(struct sk_buff *skb, if (++vl_idx < *prividx) continue; + + if (skb_tail_pointer(skb) - (unsigned char *)nest + + nla_total_size(sizeof(vxi)) >= limit) + goto nla_put_failure; + memset(&vxi, 0, sizeof(vxi)); vxi.vid = v->vid; vxi.flags = v->flags; diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index df042da422ef..511c25bf6f2a 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -6328,8 +6328,9 @@ static int rtnl_stats_get(struct sk_buff *skb, struct nlmsghdr *nlh, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0, 0, &filters, &idxattr, &prividx, extack); if (err < 0) { - /* -EMSGSIZE implies BUG in if_nlmsg_stats_size */ - WARN_ON(err == -EMSGSIZE); + /* -EMSGSIZE implies BUG in if_nlmsg_stats_size + * or a too big nested attribute. + */ kfree_skb(nskb); } else { err = rtnl_unicast(nskb, net, NETLINK_CB(skb).portid); -- cgit v1.2.3