From 04efcee6ef8d0f01eef495db047e7216d6e6e38f Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Fri, 4 Apr 2025 09:11:22 -0700 Subject: net: hold instance lock during NETDEV_CHANGE Cosmin reports an issue with ipv6_add_dev being called from NETDEV_CHANGE notifier: [ 3455.008776] ? ipv6_add_dev+0x370/0x620 [ 3455.010097] ipv6_find_idev+0x96/0xe0 [ 3455.010725] addrconf_add_dev+0x1e/0xa0 [ 3455.011382] addrconf_init_auto_addrs+0xb0/0x720 [ 3455.013537] addrconf_notify+0x35f/0x8d0 [ 3455.014214] notifier_call_chain+0x38/0xf0 [ 3455.014903] netdev_state_change+0x65/0x90 [ 3455.015586] linkwatch_do_dev+0x5a/0x70 [ 3455.016238] rtnl_getlink+0x241/0x3e0 [ 3455.019046] rtnetlink_rcv_msg+0x177/0x5e0 Similarly, linkwatch might get to ipv6_add_dev without ops lock: [ 3456.656261] ? ipv6_add_dev+0x370/0x620 [ 3456.660039] ipv6_find_idev+0x96/0xe0 [ 3456.660445] addrconf_add_dev+0x1e/0xa0 [ 3456.660861] addrconf_init_auto_addrs+0xb0/0x720 [ 3456.661803] addrconf_notify+0x35f/0x8d0 [ 3456.662236] notifier_call_chain+0x38/0xf0 [ 3456.662676] netdev_state_change+0x65/0x90 [ 3456.663112] linkwatch_do_dev+0x5a/0x70 [ 3456.663529] __linkwatch_run_queue+0xeb/0x200 [ 3456.663990] linkwatch_event+0x21/0x30 [ 3456.664399] process_one_work+0x211/0x610 [ 3456.664828] worker_thread+0x1cc/0x380 [ 3456.665691] kthread+0xf4/0x210 Reclassify NETDEV_CHANGE as a notifier that consistently runs under the instance lock. Link: https://lore.kernel.org/netdev/aac073de8beec3e531c86c101b274d434741c28e.camel@nvidia.com/ Reported-by: Cosmin Ratiu Tested-by: Cosmin Ratiu Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations") Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250404161122.3907628-1-sdf@fomichev.me Signed-off-by: Jakub Kicinski --- net/core/dev.c | 11 +---------- net/core/dev_api.c | 16 ++++++++++++++++ net/core/link_watch.c | 28 +++++++++++++++++++++++----- net/core/lock_debug.c | 2 +- net/core/rtnetlink.c | 15 +++++++++------ 5 files changed, 50 insertions(+), 22 deletions(-) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index 0608605cfc24..75e104322ad5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1518,15 +1518,7 @@ void netdev_features_change(struct net_device *dev) } EXPORT_SYMBOL(netdev_features_change); -/** - * netdev_state_change - device changes state - * @dev: device to cause notification - * - * Called to indicate a device has changed state. This function calls - * the notifier chains for netdev_chain and sends a NEWLINK message - * to the routing socket. - */ -void netdev_state_change(struct net_device *dev) +void netif_state_change(struct net_device *dev) { if (dev->flags & IFF_UP) { struct netdev_notifier_change_info change_info = { @@ -1538,7 +1530,6 @@ void netdev_state_change(struct net_device *dev) rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL); } } -EXPORT_SYMBOL(netdev_state_change); /** * __netdev_notify_peers - notify network peers about existence of @dev, diff --git a/net/core/dev_api.c b/net/core/dev_api.c index 90bafb0b1b8c..90898cd540ce 100644 --- a/net/core/dev_api.c +++ b/net/core/dev_api.c @@ -327,3 +327,19 @@ int dev_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf) return ret; } EXPORT_SYMBOL_GPL(dev_xdp_propagate); + +/** + * netdev_state_change() - device changes state + * @dev: device to cause notification + * + * Called to indicate a device has changed state. This function calls + * the notifier chains for netdev_chain and sends a NEWLINK message + * to the routing socket. + */ +void netdev_state_change(struct net_device *dev) +{ + netdev_lock_ops(dev); + netif_state_change(dev); + netdev_unlock_ops(dev); +} +EXPORT_SYMBOL(netdev_state_change); diff --git a/net/core/link_watch.c b/net/core/link_watch.c index cb04ef2b9807..864f3bbc3a4c 100644 --- a/net/core/link_watch.c +++ b/net/core/link_watch.c @@ -183,7 +183,7 @@ static void linkwatch_do_dev(struct net_device *dev) else dev_deactivate(dev); - netdev_state_change(dev); + netif_state_change(dev); } /* Note: our callers are responsible for calling netdev_tracker_free(). * This is the reason we use __dev_put() instead of dev_put(). @@ -240,7 +240,9 @@ static void __linkwatch_run_queue(int urgent_only) */ netdev_tracker_free(dev, &dev->linkwatch_dev_tracker); spin_unlock_irq(&lweventlist_lock); + netdev_lock_ops(dev); linkwatch_do_dev(dev); + netdev_unlock_ops(dev); do_dev--; spin_lock_irq(&lweventlist_lock); } @@ -253,25 +255,41 @@ static void __linkwatch_run_queue(int urgent_only) spin_unlock_irq(&lweventlist_lock); } -void linkwatch_sync_dev(struct net_device *dev) +static bool linkwatch_clean_dev(struct net_device *dev) { unsigned long flags; - int clean = 0; + bool clean = false; spin_lock_irqsave(&lweventlist_lock, flags); if (!list_empty(&dev->link_watch_list)) { list_del_init(&dev->link_watch_list); - clean = 1; + clean = true; /* We must release netdev tracker under * the spinlock protection. */ netdev_tracker_free(dev, &dev->linkwatch_dev_tracker); } spin_unlock_irqrestore(&lweventlist_lock, flags); - if (clean) + + return clean; +} + +void __linkwatch_sync_dev(struct net_device *dev) +{ + netdev_ops_assert_locked(dev); + + if (linkwatch_clean_dev(dev)) linkwatch_do_dev(dev); } +void linkwatch_sync_dev(struct net_device *dev) +{ + if (linkwatch_clean_dev(dev)) { + netdev_lock_ops(dev); + linkwatch_do_dev(dev); + netdev_unlock_ops(dev); + } +} /* Must be called with the rtnl semaphore held */ void linkwatch_run_queue(void) diff --git a/net/core/lock_debug.c b/net/core/lock_debug.c index b7f22dc92a6f..941e26c1343d 100644 --- a/net/core/lock_debug.c +++ b/net/core/lock_debug.c @@ -20,11 +20,11 @@ int netdev_debug_event(struct notifier_block *nb, unsigned long event, switch (cmd) { case NETDEV_REGISTER: case NETDEV_UP: + case NETDEV_CHANGE: netdev_ops_assert_locked(dev); fallthrough; case NETDEV_DOWN: case NETDEV_REBOOT: - case NETDEV_CHANGE: case NETDEV_UNREGISTER: case NETDEV_CHANGEMTU: case NETDEV_CHANGEADDR: diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index c23852835050..d8d03ff87a3b 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1043,7 +1043,7 @@ int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id, } EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo); -void netdev_set_operstate(struct net_device *dev, int newstate) +void netif_set_operstate(struct net_device *dev, int newstate) { unsigned int old = READ_ONCE(dev->operstate); @@ -1052,9 +1052,9 @@ void netdev_set_operstate(struct net_device *dev, int newstate) return; } while (!try_cmpxchg(&dev->operstate, &old, newstate)); - netdev_state_change(dev); + netif_state_change(dev); } -EXPORT_SYMBOL(netdev_set_operstate); +EXPORT_SYMBOL(netif_set_operstate); static void set_operstate(struct net_device *dev, unsigned char transition) { @@ -1080,7 +1080,7 @@ static void set_operstate(struct net_device *dev, unsigned char transition) break; } - netdev_set_operstate(dev, operstate); + netif_set_operstate(dev, operstate); } static unsigned int rtnl_dev_get_flags(const struct net_device *dev) @@ -3396,7 +3396,7 @@ static int do_setlink(const struct sk_buff *skb, struct net_device *dev, errout: if (status & DO_SETLINK_MODIFIED) { if ((status & DO_SETLINK_NOTIFY) == DO_SETLINK_NOTIFY) - netdev_state_change(dev); + netif_state_change(dev); if (err < 0) net_warn_ratelimited("A link change request failed with some changes committed already. Interface %s may have been left with an inconsistent configuration, please check.\n", @@ -3676,8 +3676,11 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname, nla_len(tb[IFLA_BROADCAST])); if (tb[IFLA_TXQLEN]) dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]); - if (tb[IFLA_OPERSTATE]) + if (tb[IFLA_OPERSTATE]) { + netdev_lock_ops(dev); set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE])); + netdev_unlock_ops(dev); + } if (tb[IFLA_LINKMODE]) dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]); if (tb[IFLA_GROUP]) -- cgit v1.2.3 From 445e99bdf68d62cc8cd9c129ea177b2b847d654d Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 7 Apr 2025 09:42:22 -0700 Subject: rtnetlink: Fix bad unlock balance in do_setlink(). When validate_linkmsg() fails in do_setlink(), we jump to the errout label and calls netdev_unlock_ops() even though we have not called netdev_lock_ops() as reported by syzbot. [0] Let's return an error directly in such a case. [0] WARNING: bad unlock balance detected! 6.14.0-syzkaller-12504-g8bc251e5d874 #0 Not tainted syz-executor814/5834 is trying to release lock (&dev_instance_lock_key) at: [] netdev_unlock include/linux/netdevice.h:2756 [inline] [] netdev_unlock_ops include/net/netdev_lock.h:48 [inline] [] do_setlink+0xc26/0x43a0 net/core/rtnetlink.c:3406 but there are no more locks to release! other info that might help us debug this: 1 lock held by syz-executor814/5834: #0: ffffffff900fc408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900fc408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff900fc408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd68/0x1fe0 net/core/rtnetlink.c:4064 stack backtrace: CPU: 0 UID: 0 PID: 5834 Comm: syz-executor814 Not tainted 6.14.0-syzkaller-12504-g8bc251e5d874 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_unlock_imbalance_bug+0x185/0x1a0 kernel/locking/lockdep.c:5296 __lock_release kernel/locking/lockdep.c:5535 [inline] lock_release+0x1ed/0x3e0 kernel/locking/lockdep.c:5887 __mutex_unlock_slowpath+0xee/0x800 kernel/locking/mutex.c:907 netdev_unlock include/linux/netdevice.h:2756 [inline] netdev_unlock_ops include/net/netdev_lock.h:48 [inline] do_setlink+0xc26/0x43a0 net/core/rtnetlink.c:3406 rtnl_group_changelink net/core/rtnetlink.c:3783 [inline] __rtnl_newlink net/core/rtnetlink.c:3937 [inline] rtnl_newlink+0x1619/0x1fe0 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x80f/0xd70 net/core/rtnetlink.c:6955 netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f8/0x9a0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:727 ____sys_sendmsg+0x523/0x860 net/socket.c:2566 ___sys_sendmsg net/socket.c:2620 [inline] __sys_sendmsg+0x271/0x360 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8427b614a9 Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff9b59f3a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fff9b59f578 RCX: 00007f8427b614a9 RDX: 0000000000000000 RSI: 0000200000000300 RDI: 0000000000000004 RBP: 00007f8427bd4610 R08: 000000000000000c R09: 00007fff9b59f578 R10: 000000000000001b R11: 0000000000000246 R12: 0000000000000001 R13: Fixes: 4c975fd70002 ("net: hold instance lock during NETDEV_REGISTER/UP") Reported-by: syzbot+45016fe295243a7882d3@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=45016fe295243a7882d3 Signed-off-by: Kuniyuki Iwashima Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20250407164229.24414-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski --- net/core/rtnetlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/core') diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index d8d03ff87a3b..39a5b72e861f 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3027,7 +3027,7 @@ static int do_setlink(const struct sk_buff *skb, struct net_device *dev, err = validate_linkmsg(dev, tb, extack); if (err < 0) - goto errout; + return err; if (tb[IFLA_IFNAME]) nla_strscpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ); -- cgit v1.2.3 From 0bb2f7a1ad1f11d861f58e5ee5051c8974ff9569 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 7 Apr 2025 09:33:11 -0700 Subject: net: Fix null-ptr-deref by sock_lock_init_class_and_name() and rmmod. When I ran the repro [0] and waited a few seconds, I observed two LOCKDEP splats: a warning immediately followed by a null-ptr-deref. [1] Reproduction Steps: 1) Mount CIFS 2) Add an iptables rule to drop incoming FIN packets for CIFS 3) Unmount CIFS 4) Unload the CIFS module 5) Remove the iptables rule At step 3), the CIFS module calls sock_release() for the underlying TCP socket, and it returns quickly. However, the socket remains in FIN_WAIT_1 because incoming FIN packets are dropped. At this point, the module's refcnt is 0 while the socket is still alive, so the following rmmod command succeeds. # ss -tan State Recv-Q Send-Q Local Address:Port Peer Address:Port FIN-WAIT-1 0 477 10.0.2.15:51062 10.0.0.137:445 # lsmod | grep cifs cifs 1159168 0 This highlights a discrepancy between the lifetime of the CIFS module and the underlying TCP socket. Even after CIFS calls sock_release() and it returns, the TCP socket does not die immediately in order to close the connection gracefully. While this is generally fine, it causes an issue with LOCKDEP because CIFS assigns a different lock class to the TCP socket's sk->sk_lock using sock_lock_init_class_and_name(). Once an incoming packet is processed for the socket or a timer fires, sk->sk_lock is acquired. Then, LOCKDEP checks the lock context in check_wait_context(), where hlock_class() is called to retrieve the lock class. However, since the module has already been unloaded, hlock_class() logs a warning and returns NULL, triggering the null-ptr-deref. If LOCKDEP is enabled, we must ensure that a module calling sock_lock_init_class_and_name() (CIFS, NFS, etc) cannot be unloaded while such a socket is still alive to prevent this issue. Let's hold the module reference in sock_lock_init_class_and_name() and release it when the socket is freed in sk_prot_free(). Note that sock_lock_init() clears sk->sk_owner for svc_create_socket() that calls sock_lock_init_class_and_name() for a listening socket, which clones a socket by sk_clone_lock() without GFP_ZERO. [0]: CIFS_SERVER="10.0.0.137" CIFS_PATH="//${CIFS_SERVER}/Users/Administrator/Desktop/CIFS_TEST" DEV="enp0s3" CRED="/root/WindowsCredential.txt" MNT=$(mktemp -d /tmp/XXXXXX) mount -t cifs ${CIFS_PATH} ${MNT} -o vers=3.0,credentials=${CRED},cache=none,echo_interval=1 iptables -A INPUT -s ${CIFS_SERVER} -j DROP for i in $(seq 10); do umount ${MNT} rmmod cifs sleep 1 done rm -r ${MNT} iptables -D INPUT -s ${CIFS_SERVER} -j DROP [1]: DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 10 PID: 0 at kernel/locking/lockdep.c:234 hlock_class (kernel/locking/lockdep.c:234 kernel/locking/lockdep.c:223) Modules linked in: cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs] CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Not tainted 6.14.0 #36 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:hlock_class (kernel/locking/lockdep.c:234 kernel/locking/lockdep.c:223) ... Call Trace: __lock_acquire (kernel/locking/lockdep.c:4853 kernel/locking/lockdep.c:5178) lock_acquire (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853 kernel/locking/lockdep.c:5816) _raw_spin_lock_nested (kernel/locking/spinlock.c:379) tcp_v4_rcv (./include/linux/skbuff.h:1678 ./include/net/tcp.h:2547 net/ipv4/tcp_ipv4.c:2350) ... BUG: kernel NULL pointer dereference, address: 00000000000000c4 PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Tainted: G W 6.14.0 #36 Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:__lock_acquire (kernel/locking/lockdep.c:4852 kernel/locking/lockdep.c:5178) Code: 15 41 09 c7 41 8b 44 24 20 25 ff 1f 00 00 41 09 c7 8b 84 24 a0 00 00 00 45 89 7c 24 20 41 89 44 24 24 e8 e1 bc ff ff 4c 89 e7 <44> 0f b6 b8 c4 00 00 00 e8 d1 bc ff ff 0f b6 80 c5 00 00 00 88 44 RSP: 0018:ffa0000000468a10 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ff1100010091cc38 RCX: 0000000000000027 RDX: ff1100081f09ca48 RSI: 0000000000000001 RDI: ff1100010091cc88 RBP: ff1100010091c200 R08: ff1100083fe6e228 R09: 00000000ffffbfff R10: ff1100081eca0000 R11: ff1100083fe10dc0 R12: ff1100010091cc88 R13: 0000000000000001 R14: 0000000000000000 R15: 00000000000424b1 FS: 0000000000000000(0000) GS:ff1100081f080000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000c4 CR3: 0000000002c4a003 CR4: 0000000000771ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: lock_acquire (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853 kernel/locking/lockdep.c:5816) _raw_spin_lock_nested (kernel/locking/spinlock.c:379) tcp_v4_rcv (./include/linux/skbuff.h:1678 ./include/net/tcp.h:2547 net/ipv4/tcp_ipv4.c:2350) ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205 (discriminator 1)) ip_local_deliver_finish (./include/linux/rcupdate.h:878 net/ipv4/ip_input.c:234) ip_sublist_rcv_finish (net/ipv4/ip_input.c:576) ip_list_rcv_finish (net/ipv4/ip_input.c:628) ip_list_rcv (net/ipv4/ip_input.c:670) __netif_receive_skb_list_core (net/core/dev.c:5939 net/core/dev.c:5986) netif_receive_skb_list_internal (net/core/dev.c:6040 net/core/dev.c:6129) napi_complete_done (./include/linux/list.h:37 ./include/net/gro.h:519 ./include/net/gro.h:514 net/core/dev.c:6496) e1000_clean (drivers/net/ethernet/intel/e1000/e1000_main.c:3815) __napi_poll.constprop.0 (net/core/dev.c:7191) net_rx_action (net/core/dev.c:7262 net/core/dev.c:7382) handle_softirqs (kernel/softirq.c:561) __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) irq_exit_rcu (kernel/softirq.c:680) common_interrupt (arch/x86/kernel/irq.c:280 (discriminator 14)) asm_common_interrupt (./arch/x86/include/asm/idtentry.h:693) RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/kernel/process.c:744) Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d c3 2b 15 00 fb f4 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 RSP: 0018:ffa00000000ffee8 EFLAGS: 00000202 RAX: 000000000000640b RBX: ff1100010091c200 RCX: 0000000000061aa4 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff812f30c5 RBP: 000000000000000a R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ? do_idle (kernel/sched/idle.c:186 kernel/sched/idle.c:325) default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) do_idle (kernel/sched/idle.c:186 kernel/sched/idle.c:325) cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) start_secondary (arch/x86/kernel/smpboot.c:315) common_startup_64 (arch/x86/kernel/head_64.S:421) Modules linked in: cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs] CR2: 00000000000000c4 Fixes: ed07536ed673 ("[PATCH] lockdep: annotate nfs/nfsd in-kernel sockets") Signed-off-by: Kuniyuki Iwashima Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250407163313.22682-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski --- net/core/sock.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'net/core') diff --git a/net/core/sock.c b/net/core/sock.c index 323892066def..739a79859828 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2130,6 +2130,8 @@ lenout: */ static inline void sock_lock_init(struct sock *sk) { + sk_owner_clear(sk); + if (sk->sk_kern_sock) sock_lock_init_class_and_name( sk, @@ -2226,6 +2228,9 @@ static void sk_prot_free(struct proto *prot, struct sock *sk) cgroup_sk_free(&sk->sk_cgrp_data); mem_cgroup_sk_free(sk); security_sk_free(sk); + + sk_owner_put(sk); + if (slab != NULL) kmem_cache_free(slab, sk); else -- cgit v1.2.3 From d4bac0288a2b444e468e6df9cb4ed69479ddf14a Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Tue, 8 Apr 2025 09:27:48 -0400 Subject: bpf: support SKF_NET_OFF and SKF_LL_OFF on skb frags MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Classic BPF socket filters with SKB_NET_OFF and SKB_LL_OFF fail to read when these offsets extend into frags. This has been observed with iwlwifi and reproduced with tun with IFF_NAPI_FRAGS. The below straightforward socket filter on UDP port, applied to a RAW socket, will silently miss matching packets. const int offset_proto = offsetof(struct ip6_hdr, ip6_nxt); const int offset_dport = sizeof(struct ip6_hdr) + offsetof(struct udphdr, dest); struct sock_filter filter_code[] = { BPF_STMT(BPF_LD + BPF_B + BPF_ABS, SKF_AD_OFF + SKF_AD_PKTTYPE), BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, PACKET_HOST, 0, 4), BPF_STMT(BPF_LD + BPF_B + BPF_ABS, SKF_NET_OFF + offset_proto), BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 0, 2), BPF_STMT(BPF_LD + BPF_H + BPF_ABS, SKF_NET_OFF + offset_dport), This is unexpected behavior. Socket filter programs should be consistent regardless of environment. Silent misses are particularly concerning as hard to detect. Use skb_copy_bits for offsets outside linear, same as done for non-SKF_(LL|NET) offsets. Offset is always positive after subtracting the reference threshold SKB_(LL|NET)_OFF, so is always >= skb_(mac|network)_offset. The sum of the two is an offset against skb->data, and may be negative, but it cannot point before skb->head, as skb_(mac|network)_offset would too. This appears to go back to when frag support was introduced to sk_run_filter in linux-2.4.4, before the introduction of git. The amount of code change and 8/16/32 bit duplication are unfortunate. But any attempt I made to be smarter saved very few LoC while complicating the code. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Link: https://lore.kernel.org/netdev/20250122200402.3461154-1-maze@google.com/ Link: https://elixir.bootlin.com/linux/2.4.4/source/net/core/filter.c#L244 Reported-by: Matt Moeller Co-developed-by: Maciej Żenczykowski Signed-off-by: Maciej Żenczykowski Signed-off-by: Willem de Bruijn Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20250408132833.195491-2-willemdebruijn.kernel@gmail.com Signed-off-by: Alexei Starovoitov --- net/core/filter.c | 80 ++++++++++++++++++++++++++++++------------------------- 1 file changed, 44 insertions(+), 36 deletions(-) (limited to 'net/core') diff --git a/net/core/filter.c b/net/core/filter.c index bc6828761a47..79cab4d78dc3 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -218,24 +218,36 @@ BPF_CALL_3(bpf_skb_get_nlattr_nest, struct sk_buff *, skb, u32, a, u32, x) return 0; } +static int bpf_skb_load_helper_convert_offset(const struct sk_buff *skb, int offset) +{ + if (likely(offset >= 0)) + return offset; + + if (offset >= SKF_NET_OFF) + return offset - SKF_NET_OFF + skb_network_offset(skb); + + if (offset >= SKF_LL_OFF && skb_mac_header_was_set(skb)) + return offset - SKF_LL_OFF + skb_mac_offset(skb); + + return INT_MIN; +} + BPF_CALL_4(bpf_skb_load_helper_8, const struct sk_buff *, skb, const void *, data, int, headlen, int, offset) { - u8 tmp, *ptr; + u8 tmp; const int len = sizeof(tmp); - if (offset >= 0) { - if (headlen - offset >= len) - return *(u8 *)(data + offset); - if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp))) - return tmp; - } else { - ptr = bpf_internal_load_pointer_neg_helper(skb, offset, len); - if (likely(ptr)) - return *(u8 *)ptr; - } + offset = bpf_skb_load_helper_convert_offset(skb, offset); + if (offset == INT_MIN) + return -EFAULT; - return -EFAULT; + if (headlen - offset >= len) + return *(u8 *)(data + offset); + if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp))) + return tmp; + else + return -EFAULT; } BPF_CALL_2(bpf_skb_load_helper_8_no_cache, const struct sk_buff *, skb, @@ -248,21 +260,19 @@ BPF_CALL_2(bpf_skb_load_helper_8_no_cache, const struct sk_buff *, skb, BPF_CALL_4(bpf_skb_load_helper_16, const struct sk_buff *, skb, const void *, data, int, headlen, int, offset) { - __be16 tmp, *ptr; + __be16 tmp; const int len = sizeof(tmp); - if (offset >= 0) { - if (headlen - offset >= len) - return get_unaligned_be16(data + offset); - if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp))) - return be16_to_cpu(tmp); - } else { - ptr = bpf_internal_load_pointer_neg_helper(skb, offset, len); - if (likely(ptr)) - return get_unaligned_be16(ptr); - } + offset = bpf_skb_load_helper_convert_offset(skb, offset); + if (offset == INT_MIN) + return -EFAULT; - return -EFAULT; + if (headlen - offset >= len) + return get_unaligned_be16(data + offset); + if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp))) + return be16_to_cpu(tmp); + else + return -EFAULT; } BPF_CALL_2(bpf_skb_load_helper_16_no_cache, const struct sk_buff *, skb, @@ -275,21 +285,19 @@ BPF_CALL_2(bpf_skb_load_helper_16_no_cache, const struct sk_buff *, skb, BPF_CALL_4(bpf_skb_load_helper_32, const struct sk_buff *, skb, const void *, data, int, headlen, int, offset) { - __be32 tmp, *ptr; + __be32 tmp; const int len = sizeof(tmp); - if (likely(offset >= 0)) { - if (headlen - offset >= len) - return get_unaligned_be32(data + offset); - if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp))) - return be32_to_cpu(tmp); - } else { - ptr = bpf_internal_load_pointer_neg_helper(skb, offset, len); - if (likely(ptr)) - return get_unaligned_be32(ptr); - } + offset = bpf_skb_load_helper_convert_offset(skb, offset); + if (offset == INT_MIN) + return -EFAULT; - return -EFAULT; + if (headlen - offset >= len) + return get_unaligned_be32(data + offset); + if (!skb_copy_bits(skb, offset, &tmp, sizeof(tmp))) + return be32_to_cpu(tmp); + else + return -EFAULT; } BPF_CALL_2(bpf_skb_load_helper_32_no_cache, const struct sk_buff *, skb, -- cgit v1.2.3 From f0433eea468810aebd61d0b9d095e9acd6bea2ed Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sat, 12 Apr 2025 16:30:11 -0700 Subject: net: don't mix device locking in dev_close_many() calls Lockdep found the following dependency: &dev_instance_lock_key#3 --> &rdev->wiphy.mtx --> &net->xdp.lock --> &xs->mutex --> &dev_instance_lock_key#3 The first dependency is the problem. wiphy mutex should be outside the instance locks. The problem happens in notifiers (as always) for CLOSE. We only hold the instance lock for ops locked devices during CLOSE, and WiFi netdevs are not ops locked. Unfortunately, when we dev_close_many() during netns dismantle we may be holding the instance lock of _another_ netdev when issuing a CLOSE for a WiFi device. Lockdep's "Possible unsafe locking scenario" only prints 3 locks and we have 4, plus I think we'd need 3 CPUs, like this: CPU0 CPU1 CPU2 ---- ---- ---- lock(&xs->mutex); lock(&dev_instance_lock_key#3); lock(&rdev->wiphy.mtx); lock(&net->xdp.lock); lock(&xs->mutex); lock(&rdev->wiphy.mtx); lock(&dev_instance_lock_key#3); Tho, I don't think that's possible as CPU1 and CPU2 would be under rtnl_lock. Even if we have per-netns rtnl_lock and wiphy can span network namespaces - CPU0 and CPU1 must be in the same netns to see dev_instance_lock, so CPU0 can't be installing a socket as CPU1 is tearing the netns down. Regardless, our expected lock ordering is that wiphy lock is taken before instance locks, so let's fix this. Go over the ops locked and non-locked devices separately. Note that calling dev_close_many() on an empty list is perfectly fine. All processing (including RCU syncs) are conditional on the list not being empty, already. Fixes: 7e4d784f5810 ("net: hold netdev instance lock during rtnetlink operations") Reported-by: syzbot+6f588c78bf765b62b450@syzkaller.appspotmail.com Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20250412233011.309762-1-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/core/dev.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index 75e104322ad5..5fcbc66d865e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -11932,15 +11932,24 @@ void unregister_netdevice_many_notify(struct list_head *head, BUG_ON(dev->reg_state != NETREG_REGISTERED); } - /* If device is running, close it first. */ + /* If device is running, close it first. Start with ops locked... */ list_for_each_entry(dev, head, unreg_list) { - list_add_tail(&dev->close_list, &close_head); - netdev_lock_ops(dev); + if (netdev_need_ops_lock(dev)) { + list_add_tail(&dev->close_list, &close_head); + netdev_lock(dev); + } + } + dev_close_many(&close_head, true); + /* ... now unlock them and go over the rest. */ + list_for_each_entry(dev, head, unreg_list) { + if (netdev_need_ops_lock(dev)) + netdev_unlock(dev); + else + list_add_tail(&dev->close_list, &close_head); } dev_close_many(&close_head, true); list_for_each_entry(dev, head, unreg_list) { - netdev_unlock_ops(dev); /* And unlink it from device chain. */ unlist_netdevice(dev); netdev_lock(dev); -- cgit v1.2.3 From 2d300ce0b783ba74420052ed3a12010ac93bdb08 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Mon, 14 Apr 2025 20:20:21 +0300 Subject: net: fib_rules: Fix iif / oif matching on L3 master device Before commit 40867d74c374 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices") it was possible to use FIB rules to match on a L3 domain. This was done by having a FIB rule match on iif / oif being a L3 master device. It worked because prior to the FIB rule lookup the iif / oif fields in the flow structure were reset to the index of the L3 master device to which the input / output device was enslaved to. The above scheme made it impossible to match on the original input / output device. Therefore, cited commit stopped overwriting the iif / oif fields in the flow structure and instead stored the index of the enslaving L3 master device in a new field ('flowi_l3mdev') in the flow structure. While the change enabled new use cases, it broke the original use case of matching on a L3 domain. Fix this by interpreting the iif / oif matching on a L3 master device as a match against the L3 domain. In other words, if the iif / oif in the FIB rule points to a L3 master device, compare the provided index against 'flowi_l3mdev' rather than 'flowi_{i,o}if'. Before cited commit, a FIB rule that matched on 'iif vrf1' would only match incoming traffic from devices enslaved to 'vrf1'. With the proposed change (i.e., comparing against 'flowi_l3mdev'), the rule would also match traffic originating from a socket bound to 'vrf1'. Avoid that by adding a new flow flag ('FLOWI_FLAG_L3MDEV_OIF') that indicates if the L3 domain was derived from the output interface or the input interface (when not set) and take this flag into account when evaluating the FIB rule against the flow structure. Avoid unnecessary checks in the data path by detecting that a rule matches on a L3 master device when the rule is installed and marking it as such. Tested using the following script [1]. Output before 40867d74c374 (v5.4.291): default dev dummy1 table 100 scope link default dev dummy1 table 200 scope link Output after 40867d74c374: default dev dummy1 table 300 scope link default dev dummy1 table 300 scope link Output with this patch: default dev dummy1 table 100 scope link default dev dummy1 table 200 scope link [1] #!/bin/bash ip link add name vrf1 up type vrf table 10 ip link add name dummy1 up master vrf1 type dummy sysctl -wq net.ipv4.conf.all.forwarding=1 sysctl -wq net.ipv4.conf.all.rp_filter=0 ip route add table 100 default dev dummy1 ip route add table 200 default dev dummy1 ip route add table 300 default dev dummy1 ip rule add prio 0 oif vrf1 table 100 ip rule add prio 1 iif vrf1 table 200 ip rule add prio 2 table 300 ip route get 192.0.2.1 oif dummy1 fibmatch ip route get 192.0.2.1 iif dummy1 from 198.51.100.1 fibmatch Fixes: 40867d74c374 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices") Reported-by: hanhuihui Closes: https://lore.kernel.org/netdev/ec671c4f821a4d63904d0da15d604b75@huawei.com/ Signed-off-by: Ido Schimmel Acked-by: David Ahern Link: https://patch.msgid.link/20250414172022.242991-2-idosch@nvidia.com Signed-off-by: Jakub Kicinski --- net/core/fib_rules.c | 48 ++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 40 insertions(+), 8 deletions(-) (limited to 'net/core') diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c index 4bc64d912a1c..7af302080a66 100644 --- a/net/core/fib_rules.c +++ b/net/core/fib_rules.c @@ -257,6 +257,24 @@ static int nla_put_port_range(struct sk_buff *skb, int attrtype, return nla_put(skb, attrtype, sizeof(*range), range); } +static bool fib_rule_iif_match(const struct fib_rule *rule, int iifindex, + const struct flowi *fl) +{ + u8 iif_is_l3_master = READ_ONCE(rule->iif_is_l3_master); + + return iif_is_l3_master ? l3mdev_fib_rule_iif_match(fl, iifindex) : + fl->flowi_iif == iifindex; +} + +static bool fib_rule_oif_match(const struct fib_rule *rule, int oifindex, + const struct flowi *fl) +{ + u8 oif_is_l3_master = READ_ONCE(rule->oif_is_l3_master); + + return oif_is_l3_master ? l3mdev_fib_rule_oif_match(fl, oifindex) : + fl->flowi_oif == oifindex; +} + static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops, struct flowi *fl, int flags, struct fib_lookup_arg *arg) @@ -264,11 +282,11 @@ static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops, int iifindex, oifindex, ret = 0; iifindex = READ_ONCE(rule->iifindex); - if (iifindex && (iifindex != fl->flowi_iif)) + if (iifindex && !fib_rule_iif_match(rule, iifindex, fl)) goto out; oifindex = READ_ONCE(rule->oifindex); - if (oifindex && (oifindex != fl->flowi_oif)) + if (oifindex && !fib_rule_oif_match(rule, oifindex, fl)) goto out; if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask) @@ -736,16 +754,20 @@ static int fib_nl2rule_rtnl(struct fib_rule *nlrule, struct net_device *dev; dev = __dev_get_by_name(nlrule->fr_net, nlrule->iifname); - if (dev) + if (dev) { nlrule->iifindex = dev->ifindex; + nlrule->iif_is_l3_master = netif_is_l3_master(dev); + } } if (tb[FRA_OIFNAME]) { struct net_device *dev; dev = __dev_get_by_name(nlrule->fr_net, nlrule->oifname); - if (dev) + if (dev) { nlrule->oifindex = dev->ifindex; + nlrule->oif_is_l3_master = netif_is_l3_master(dev); + } } return 0; @@ -1336,11 +1358,17 @@ static void attach_rules(struct list_head *rules, struct net_device *dev) list_for_each_entry(rule, rules, list) { if (rule->iifindex == -1 && - strcmp(dev->name, rule->iifname) == 0) + strcmp(dev->name, rule->iifname) == 0) { WRITE_ONCE(rule->iifindex, dev->ifindex); + WRITE_ONCE(rule->iif_is_l3_master, + netif_is_l3_master(dev)); + } if (rule->oifindex == -1 && - strcmp(dev->name, rule->oifname) == 0) + strcmp(dev->name, rule->oifname) == 0) { WRITE_ONCE(rule->oifindex, dev->ifindex); + WRITE_ONCE(rule->oif_is_l3_master, + netif_is_l3_master(dev)); + } } } @@ -1349,10 +1377,14 @@ static void detach_rules(struct list_head *rules, struct net_device *dev) struct fib_rule *rule; list_for_each_entry(rule, rules, list) { - if (rule->iifindex == dev->ifindex) + if (rule->iifindex == dev->ifindex) { WRITE_ONCE(rule->iifindex, -1); - if (rule->oifindex == dev->ifindex) + WRITE_ONCE(rule->iif_is_l3_master, false); + } + if (rule->oifindex == dev->ifindex) { WRITE_ONCE(rule->oifindex, -1); + WRITE_ONCE(rule->oif_is_l3_master, false); + } } } -- cgit v1.2.3 From 4798cfa2097f0833d54d8f5ce20ef14631917839 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 15 Apr 2025 08:15:52 -0700 Subject: net: don't try to ops lock uninitialized devs We need to be careful when operating on dev while in rtnl_create_link(). Some devices (vxlan) initialize netdev_ops in ->newlink, so later on. Avoid using netdev_lock_ops(), the device isn't registered so we cannot legally call its ops or generate any notifications for it. netdev_ops_assert_locked_or_invisible() is safe to use, it checks registration status first. Reported-by: syzbot+de1c7d68a10e3f123bdd@syzkaller.appspotmail.com Fixes: 04efcee6ef8d ("net: hold instance lock during NETDEV_CHANGE") Acked-by: Stanislav Fomichev Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250415151552.768373-1-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/core/dev.c | 2 ++ net/core/rtnetlink.c | 5 +---- 2 files changed, 3 insertions(+), 4 deletions(-) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index 5fcbc66d865e..1be7cb73a602 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1520,6 +1520,8 @@ EXPORT_SYMBOL(netdev_features_change); void netif_state_change(struct net_device *dev) { + netdev_ops_assert_locked_or_invisible(dev); + if (dev->flags & IFF_UP) { struct netdev_notifier_change_info change_info = { .info.dev = dev, diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 39a5b72e861f..c5a7f41982a5 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3676,11 +3676,8 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname, nla_len(tb[IFLA_BROADCAST])); if (tb[IFLA_TXQLEN]) dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]); - if (tb[IFLA_OPERSTATE]) { - netdev_lock_ops(dev); + if (tb[IFLA_OPERSTATE]) set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE])); - netdev_unlock_ops(dev); - } if (tb[IFLA_LINKMODE]) dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]); if (tb[IFLA_GROUP]) -- cgit v1.2.3 From d3153c3b42707d26c81083b426f2ef0951bce545 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 17 Apr 2025 18:53:17 -0700 Subject: net: fix the missing unlock for detached devices The combined condition was left as is when we converted from __dev_get_by_index() to netdev_get_by_index_lock(). There was no need to undo anything with the former, for the latter we need an unlock. Fixes: 1d22d3060b9b ("net: drop rtnl_lock for queue_mgmt operations") Reviewed-by: Mina Almasry Link: https://patch.msgid.link/20250418015317.1954107-1-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/core/netdev-genl.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'net/core') diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index 5d7af50fe702..230743bdbb14 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -861,14 +861,17 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) mutex_lock(&priv->lock); + err = 0; netdev = netdev_get_by_index_lock(genl_info_net(info), ifindex); - if (!netdev || !netif_device_present(netdev)) { + if (!netdev) { err = -ENODEV; goto err_unlock_sock; } - - if (!netdev_need_ops_lock(netdev)) { + if (!netif_device_present(netdev)) + err = -ENODEV; + else if (!netdev_need_ops_lock(netdev)) err = -EOPNOTSUPP; + if (err) { NL_SET_BAD_ATTR(info->extack, info->attrs[NETDEV_A_DEV_IFINDEX]); goto err_unlock; -- cgit v1.2.3 From 9e8d1013b0c38910cbc9e60de74dbe883878469d Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Wed, 16 Apr 2025 18:01:25 +0200 Subject: net: selftests: initialize TCP header and skb payload with zero Zero-initialize TCP header via memset() to avoid garbage values that may affect checksum or behavior during test transmission. Also zero-fill allocated payload and padding regions using memset() after skb_put(), ensuring deterministic content for all outgoing test packets. Fixes: 3e1e58d64c3d ("net: add generic selftest support") Signed-off-by: Oleksij Rempel Cc: stable@vger.kernel.org Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250416160125.2914724-1-o.rempel@pengutronix.de Signed-off-by: Paolo Abeni --- net/core/selftests.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'net/core') diff --git a/net/core/selftests.c b/net/core/selftests.c index e99ae983fca9..35f807ea9952 100644 --- a/net/core/selftests.c +++ b/net/core/selftests.c @@ -100,10 +100,10 @@ static struct sk_buff *net_test_get_skb(struct net_device *ndev, ehdr->h_proto = htons(ETH_P_IP); if (attr->tcp) { + memset(thdr, 0, sizeof(*thdr)); thdr->source = htons(attr->sport); thdr->dest = htons(attr->dport); thdr->doff = sizeof(struct tcphdr) / 4; - thdr->check = 0; } else { uhdr->source = htons(attr->sport); uhdr->dest = htons(attr->dport); @@ -144,10 +144,18 @@ static struct sk_buff *net_test_get_skb(struct net_device *ndev, attr->id = net_test_next_id; shdr->id = net_test_next_id++; - if (attr->size) - skb_put(skb, attr->size); - if (attr->max_size && attr->max_size > skb->len) - skb_put(skb, attr->max_size - skb->len); + if (attr->size) { + void *payload = skb_put(skb, attr->size); + + memset(payload, 0, attr->size); + } + + if (attr->max_size && attr->max_size > skb->len) { + size_t pad_len = attr->max_size - skb->len; + void *pad = skb_put(skb, pad_len); + + memset(pad, 0, pad_len); + } skb->csum = 0; skb->ip_summed = CHECKSUM_PARTIAL; -- cgit v1.2.3 From c03a49f3093a4903c8a93c8b5c9a297b5343b169 Mon Sep 17 00:00:00 2001 From: Justin Iurman Date: Wed, 16 Apr 2025 18:07:16 +0200 Subject: net: lwtunnel: disable BHs when required In lwtunnel_{output|xmit}(), dev_xmit_recursion() may be called in preemptible scope for PREEMPT kernels. This patch disables BHs before calling dev_xmit_recursion(). BHs are re-enabled only at the end, since we must ensure the same CPU is used for both dev_xmit_recursion_inc() and dev_xmit_recursion_dec() (and any other recursion levels in some cases) in order to maintain valid per-cpu counters. Reported-by: Alexei Starovoitov Closes: https://lore.kernel.org/netdev/CAADnVQJFWn3dBFJtY+ci6oN1pDFL=TzCmNbRgey7MdYxt_AP2g@mail.gmail.com/ Reported-by: Eduard Zingerman Closes: https://lore.kernel.org/netdev/m2h62qwf34.fsf@gmail.com/ Fixes: 986ffb3a57c5 ("net: lwtunnel: fix recursion loops") Signed-off-by: Justin Iurman Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250416160716.8823-1-justin.iurman@uliege.be Signed-off-by: Paolo Abeni --- net/core/lwtunnel.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) (limited to 'net/core') diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c index e39a459540ec..60f27cb4e54f 100644 --- a/net/core/lwtunnel.c +++ b/net/core/lwtunnel.c @@ -333,6 +333,8 @@ int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) struct dst_entry *dst; int ret; + local_bh_disable(); + if (dev_xmit_recursion()) { net_crit_ratelimited("%s(): recursion limit reached on datapath\n", __func__); @@ -348,8 +350,10 @@ int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) lwtstate = dst->lwtstate; if (lwtstate->type == LWTUNNEL_ENCAP_NONE || - lwtstate->type > LWTUNNEL_ENCAP_MAX) - return 0; + lwtstate->type > LWTUNNEL_ENCAP_MAX) { + ret = 0; + goto out; + } ret = -EOPNOTSUPP; rcu_read_lock(); @@ -364,11 +368,13 @@ int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) if (ret == -EOPNOTSUPP) goto drop; - return ret; + goto out; drop: kfree_skb(skb); +out: + local_bh_enable(); return ret; } EXPORT_SYMBOL_GPL(lwtunnel_output); @@ -380,6 +386,8 @@ int lwtunnel_xmit(struct sk_buff *skb) struct dst_entry *dst; int ret; + local_bh_disable(); + if (dev_xmit_recursion()) { net_crit_ratelimited("%s(): recursion limit reached on datapath\n", __func__); @@ -396,8 +404,10 @@ int lwtunnel_xmit(struct sk_buff *skb) lwtstate = dst->lwtstate; if (lwtstate->type == LWTUNNEL_ENCAP_NONE || - lwtstate->type > LWTUNNEL_ENCAP_MAX) - return 0; + lwtstate->type > LWTUNNEL_ENCAP_MAX) { + ret = 0; + goto out; + } ret = -EOPNOTSUPP; rcu_read_lock(); @@ -412,11 +422,13 @@ int lwtunnel_xmit(struct sk_buff *skb) if (ret == -EOPNOTSUPP) goto drop; - return ret; + goto out; drop: kfree_skb(skb); +out: + local_bh_enable(); return ret; } EXPORT_SYMBOL_GPL(lwtunnel_xmit); @@ -428,6 +440,8 @@ int lwtunnel_input(struct sk_buff *skb) struct dst_entry *dst; int ret; + DEBUG_NET_WARN_ON_ONCE(!in_softirq()); + if (dev_xmit_recursion()) { net_crit_ratelimited("%s(): recursion limit reached on datapath\n", __func__); -- cgit v1.2.3