From 82e9343260dfc6dda6349f285d9a5eac3e0738d7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=A9r=C3=A9my=20Jean?= Date: Fri, 14 Aug 2026 10:20:05 +0000 Subject: nsfs: keep namespace tree fields stable until after RCU grace period MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit struct ns_common overlays struct ns_tree with the rcu_head used by kfree_rcu(). That lets the deferred-free machinery overwrite ns_id and __ns_ref_active as soon as a namespace is queued for freeing, even though nsfs tree walkers may still read those fields under RCU after ns_tree_remove(). KASAN reports slab UAF. Keep the tree state and deferred-free callback storage separate. Namespace tree readers can then continue to validate and take references until the grace period has elapsed. Signed-off-by: Jérémy Jean Link: https://patch.msgid.link/20260814102005.1939777-1-Jeremy.Jean@oss.cyber.gouv.fr Signed-off-by: Christian Brauner (Amutable) --- include/linux/ns/ns_common_types.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ns/ns_common_types.h b/include/linux/ns/ns_common_types.h index ea45c54e4435..6ed6b497831c 100644 --- a/include/linux/ns/ns_common_types.h +++ b/include/linux/ns/ns_common_types.h @@ -116,10 +116,8 @@ struct ns_common { struct dentry *stashed; const struct proc_ns_operations *ops; unsigned int inum; - union { - struct ns_tree; - struct rcu_head ns_rcu; - }; + struct ns_tree; + struct rcu_head ns_rcu; }; #define to_ns_common(__ns) \ -- cgit v1.2.3 From ffe0486b139e45cd9c9ca2584f04a1910fe4f8a6 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 19 Aug 2026 15:38:53 +0200 Subject: console: fix /dev/kmsg reference in flags kernel doc Fix typo in the CON_EXTENDED flag kernel doc which is supposed to refer to '/dev/kmsg'. Fixes: 717a5651b109 ("console: Use BIT() macros for @flags values") Signed-off-by: Johan Hovold Reviewed-by: Petr Mladek Link: https://patch.msgid.link/20260819133853.286658-1-johan@kernel.org Signed-off-by: Petr Mladek --- include/linux/console.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/console.h b/include/linux/console.h index d624200cfc17..502d1abe3f50 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -173,7 +173,7 @@ static inline void con_debug_leave(void) { } * @CON_BRL: Indicates a braille device which is exempt from * receiving the printk spam for obvious reasons. * @CON_EXTENDED: The console supports the extended output format of - * /dev/kmesg which requires a larger output buffer. + * /dev/kmsg which requires a larger output buffer. * @CON_SUSPENDED: Indicates if a console is suspended. If true, the * printing callbacks must not be called. * @CON_NBCON: Console can operate outside of the legacy style console_lock -- cgit v1.2.3 From fed0b33e6c584986ba70018ec9f9787a98216e64 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 27 Aug 2026 14:43:00 +0100 Subject: netfs: Fix readahead synchronisation issues by loading all folios upfront There are some synchronisation issues that derive from the app thread adding more folios to the rolling buffer whilst the collector thread is looking at them or trying to clear them, such as determining the setting of front_folio_order when the next folio hasn't been added yet, The reason for the rolling buffer approach is that loading the buffer upfront and then dropping all the refs just acquired is quite a slow operation, and loading progressively allows some of the cost to be deferred until after at least some of the I/O is started. Instead, a better way is to load all the folios into the rolling buffer upfront - and then drop the refs later, once the I/O is in progress. (Even better would be for the refs not to be there at all.) Fix this by changing the rolling buffer loader to load all the folios selected by the VM for readahead upfront into the folio queue. The folio queue is allocated a batch worth at a time as we don't know how many folios are involved (the readahead_control struct, alas, has a page count, not a folio count). The folio refs acquired from readahead are then dropped in bulk once the first subrequest is dispatched as it's quite a slow operation. The collector waits for NETFS_RREQ_NEED_PUT_RA_REFS to be cleared so that it doesn't unlock folios before the xarray has been scanned for them. This simplifies the buffer handling later and isn't noticeably slower as the xarray doesn't need to be modified and the folios are all already pre-locked. Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Link: https://sashiko.dev/#/patchset/20260824120224.504575-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260827134304.2075713-8-dhowells@redhat.com Acked-by: Paulo Alcantara cc: Paulo Alcantara (Red Hat) cc: Matthew Wilcox cc: netfs@lists.linux.dev cc: linux-mm@kvack.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) --- include/linux/netfs.h | 1 + include/linux/rolling_buffer.h | 6 +++--- 2 files changed, 4 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netfs.h b/include/linux/netfs.h index f837a501008c..5c538d0c5d79 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -278,6 +278,7 @@ struct netfs_io_request { #define NETFS_RREQ_FOLIO_COPY_TO_CACHE 10 /* Copy current folio to cache from read */ #define NETFS_RREQ_UPLOAD_TO_SERVER 11 /* Need to write to the server */ #define NETFS_RREQ_USE_IO_ITER 12 /* Use ->io_iter rather than ->i_pages */ +#define NETFS_RREQ_NEED_PUT_RA_REFS 17 /* Need to put the folio refs RA gave us */ #define NETFS_RREQ_USE_PGPRIV2 31 /* [DEPRECATED] Use PG_private_2 to mark * write to cache on read */ const struct netfs_request_ops *netfs_ops; diff --git a/include/linux/rolling_buffer.h b/include/linux/rolling_buffer.h index 9e5dad29669c..a97f7cfaacaa 100644 --- a/include/linux/rolling_buffer.h +++ b/include/linux/rolling_buffer.h @@ -45,9 +45,9 @@ struct rolling_buffer_snapshot { int rolling_buffer_init(struct rolling_buffer *roll, unsigned int rreq_id, unsigned int direction, gfp_t gfp); int rolling_buffer_make_space(struct rolling_buffer *roll, gfp_t gfp); -ssize_t rolling_buffer_load_from_ra(struct rolling_buffer *roll, - struct readahead_control *ractl, - struct folio_batch *put_batch); +ssize_t rolling_buffer_bulk_load_from_ra(struct rolling_buffer *roll, + struct readahead_control *ractl, + unsigned int rreq_id, gfp_t gfp); ssize_t rolling_buffer_append(struct rolling_buffer *roll, struct folio *folio, unsigned int flags, gfp_t gfp); struct folio_queue *rolling_buffer_delete_spent(struct rolling_buffer *roll); -- cgit v1.2.3 From 533203c4183123dad8ffecd694e7573a0ccd0da0 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 27 Aug 2026 14:43:01 +0100 Subject: netfs: Mark folios with COPY_TO_CACHE whilst issuing subreqs Mark folios with NETFS_FOLIO_COPY_TO_CACHE whilst issuing subreqs rather than when collecting them. This means that the collector thread doesn't have to try and keep track of which subreqs contribute to which folios - and thus which folios will need to be copied to the cache because at least one byte wasn't in the cache. Instead, this is marked on the folios up front and the collector need only consider the folios. For PG_private_2-using filesystems, PG_private_2 is set instead of NETFS_FOLIO_COPY_TO_CACHE, but otherwise it works the same. The NETFS_RREQ_COPY_TO_CACHE is replaced with NETFS_RREQ_CANCEL_CACHING, which is now set if caching fails somewhere, thereby causing the collection thread to cancel the copy-to-cache marks on the remaining folios. Signed-off-by: David Howells Link: https://patch.msgid.link/20260827134304.2075713-9-dhowells@redhat.com Acked-by: Paulo Alcantara cc: Paulo Alcantara (Red Hat) cc: Matthew Wilcox cc: netfs@lists.linux.dev cc: linux-mm@kvack.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) --- include/linux/netfs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 5c538d0c5d79..9881f4afdc0c 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -275,7 +275,7 @@ struct netfs_io_request { #define NETFS_RREQ_SHORT_TRANSFER 5 /* Set if we have a short transfer */ #define NETFS_RREQ_OFFLOAD_COLLECTION 8 /* Offload collection to workqueue */ #define NETFS_RREQ_NO_UNLOCK_FOLIO 9 /* Don't unlock no_unlock_folio on completion */ -#define NETFS_RREQ_FOLIO_COPY_TO_CACHE 10 /* Copy current folio to cache from read */ +#define NETFS_RREQ_CANCEL_CACHING 10 /* Set to cancel caching */ #define NETFS_RREQ_UPLOAD_TO_SERVER 11 /* Need to write to the server */ #define NETFS_RREQ_USE_IO_ITER 12 /* Use ->io_iter rather than ->i_pages */ #define NETFS_RREQ_NEED_PUT_RA_REFS 17 /* Need to put the folio refs RA gave us */ -- cgit v1.2.3 From e00827a4d0cfebf8d78dfd0a9a024237f57c9273 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 27 Aug 2026 14:43:02 +0100 Subject: netfs: Fix read progress reporting For really big read RPC ops that span multiple folios, netfslib allows the filesystem to give progress notifications to wake up the collector thread to do a collection of folios that have now been fetched, even if the RPC is still ongoing, thereby allowing the application to make progress. This works by taking the current rreq->cleaned_to value (which indicates which folios have been unlocked) and adding the stashed size of the next folio to it. cleaned_to, however, is subject to 64-bit tearing on a 32-bit arch. Fix this by stashing the next progress notification point as a size_t (which won't tear) to be added to rreq->start (which won't change), with the collector thread calculating that from cleaned_to plus the next folio size. Further, however, if the folios are small, the collector thread gets constantly woken up - which has a negative performance impact on the system. Fix that too by setting a minimum trigger of 256KiB or the size of the folio at the front of the queue, whichever is larger. Note that this has an issue that different subreqs have different need-to-be-cached properties; this is solved by a preceding patch that marks the property on the folios whilst issuing subreqs rather than when collecting them. Also, make sure rreq->cleaned_to is initialised up front, along with rreq->collected_to and stream->collected_to. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Link: https://sashiko.dev/#/patchset/20260804100224.2748935-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260827134304.2075713-10-dhowells@redhat.com Acked-by: Paulo Alcantara cc: Paulo Alcantara cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) --- include/linux/netfs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 9881f4afdc0c..b4dd32863dd4 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -246,6 +246,7 @@ struct netfs_io_request { unsigned long long submitted; /* Amount submitted for I/O so far */ unsigned long long len; /* Length of the request */ size_t transferred; /* Amount to be indicated as transferred */ + size_t progress_at; /* Report read progress when hit this much read */ long error; /* 0 or error that occurred */ unsigned long long i_size; /* Size of the file */ unsigned long long start; /* Start position */ @@ -262,7 +263,6 @@ struct netfs_io_request { atomic_t subreq_counter; /* Next subreq->debug_index */ unsigned int nr_group_rel; /* Number of refs to release on ->group */ spinlock_t lock; /* Lock for queuing subreqs */ - unsigned char front_folio_order; /* Order (size) of front folio */ enum netfs_io_origin origin; /* Origin of the request */ bool direct_bv_unpin; /* T if direct_bv[] must be unpinned */ refcount_t ref; -- cgit v1.2.3 From 5a88f78df753993469dab4d1831f8fb4256a9468 Mon Sep 17 00:00:00 2001 From: "Cen Zhang (Microsoft)" Date: Fri, 14 Aug 2026 00:09:44 -0400 Subject: reboot: fix cad_pid use-after-free race cad_pid is a single kernel-wide struct pid pointer. proc_do_cad_pid() reads it and passes it to pid_vnr() without protecting the lifetime of the referenced struct pid. A concurrent writer can replace cad_pid and drop the final reference to the old struct pid after the reader has loaded the pointer but before pid_vnr() has finished dereferencing it, causing a use-after-free. kill_cad_pid() has the same lifetime race when it passes cad_pid to kill_pid(). At the time this issue was reported, an unprivileged user could reach the sysctl through user and PID namespaces because cad_pid was registered in pid_table[]. Moving cad_pid back to the global reboot sysctl table corrected that namespace and permission mismatch, but did not fix the underlying lifetime race. Fix this by treating cad_pid as an RCU-protected pointer at both read sites and by waiting for a grace period before dropping the old reference on the write side. call_rcu(&old_pid->rcu, ...) cannot be used here because free_pid() also queues pid->rcu; queueing the same rcu_head twice can corrupt the RCU callback list. Original KASAN crash stack: kernel/pid.c:545 pid_nr_ns() # reads freed pid->level kernel/pid.c:556 pid_vnr() # calls pid_nr_ns() kernel/pid.c:775 proc_do_cad_pid() # calls pid_vnr(cad_pid) Fixes: 9ec52099e4b8 ("[PATCH] replace cad_pid by a struct pid") Reported-by: AutonomousCodeSecurity@microsoft.com Closes: https://lore.kernel.org/all/20260717210143.4734-1-blbllhy@gmail.com/ Link: https://lore.kernel.org/all/alz5ZYLE4kaq_v2P@redhat.com/ Link: https://lore.kernel.org/all/al4ICz9biJKtdZc4@redhat.com/ Suggested-by: Mateusz Guzik Suggested-by: Bradley Morgan Suggested-by: Oleg Nesterov Suggested-by: Eric W. Biederman Suggested-by: Pavel Tikhomirov Cc: stable@vger.kernel.org Signed-off-by: Cen Zhang (Microsoft) Link: https://patch.msgid.link/20260814040944.16561-1-blbllhy@gmail.com Reviewed-by: Bradley Morgan Reviewed-by: Oleg Nesterov Reviewed-by: Pavel Tikhomirov Signed-off-by: Christian Brauner (Amutable) --- include/linux/sched.h | 2 +- include/linux/sched/signal.h | 5 +---- 2 files changed, 2 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/sched.h b/include/linux/sched.h index 3f100d69b053..fdafd164a42d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1778,7 +1778,7 @@ static inline bool is_lazy_mmu_mode_active(void) } #endif -extern struct pid *cad_pid; +extern struct pid __rcu *cad_pid; /* * Per process flags diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 584ae88b435e..d45a5476b97d 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -562,10 +562,7 @@ static inline sigset_t *sigmask_to_save(void) return res; } -static inline int kill_cad_pid(int sig, int priv) -{ - return kill_pid(cad_pid, sig, priv); -} +int kill_cad_pid(int sig, int priv); /* These can be the second arg to send_sig_info/send_group_sig_info. */ #define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0) -- cgit v1.2.3 From 6809da6e9c08ccc9a09cb0a48c61471679274aaa Mon Sep 17 00:00:00 2001 From: Xixin Liu Date: Tue, 18 Aug 2026 17:10:00 +0800 Subject: perf: RISC-V: store available counter mask as bitmap The available-counter mask was a single unsigned long, but iteration uses RISCV_MAX_COUNTERS, which is 64. On RV32 that reads past the object. Filling with an unsigned-long bit at index 32 and above is also wrong. Use DECLARE_BITMAP and set_bit/bitmap helpers. Walk each bitmap word into CFG_MATCH when checking events, when allocating an index, and when stopping all counters. Set the counter base to i times BITS_PER_LONG. Share the CFG_MATCH ecall through a small helper so the 32-bit argument split is not duplicated. On qemu-system-riscv32 the probe bitmap has bits above XLEN set, so the first word alone is not enough. Fixes: e9991434596f ("RISC-V: Add perf platform driver based on SBI PMU extension") Assisted-by: DeepSeek:deepseek-v3 Signed-off-by: Xixin Liu Link: https://patch.msgid.link/prpmask02cmap.v2.1786434000.git.liuxixin@kylinos.cn Cc: stable@kernel.org [pjw@kernel.org: updated to apply; fixed checkpatch.pl issues] Signed-off-by: Paul Walmsley --- include/linux/perf/riscv_pmu.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/perf/riscv_pmu.h b/include/linux/perf/riscv_pmu.h index f82a28040594..ecaa40370830 100644 --- a/include/linux/perf/riscv_pmu.h +++ b/include/linux/perf/riscv_pmu.h @@ -55,7 +55,7 @@ struct riscv_pmu { irqreturn_t (*handle_irq)(int irq_num, void *dev); - unsigned long cmask; + DECLARE_BITMAP(cmask, RISCV_MAX_COUNTERS); u64 (*ctr_read)(struct perf_event *event); int (*ctr_get_idx)(struct perf_event *event); int (*ctr_get_width)(int idx); -- cgit v1.2.3 From e6031f02269c0f51cf67886d177f02bc300b47cd Mon Sep 17 00:00:00 2001 From: Ivan Pustogarov Date: Thu, 3 Sep 2026 17:26:16 +0200 Subject: wifi: mac80211: avoid out-of-bounds read for empty PREQ elements ieee80211_mesh_preq_size_ok() derives the location of the PREQ bottom fields before checking whether the element contains even the fixed header. ieee80211_mesh_hwmp_preq_get_bottom() reads the flags byte to account for the optional Address Extension field. Consequently, an empty PREQ element causes a one-byte read beyond its declared payload. Move the helper call after both size checks, so the bottom fields are only accessed when they are present. Fixes: 8b40b1d24a60 ("wifi: mac80211: Fix overread in PREQ frame processing") Cc: stable@vger.kernel.org Signed-off-by: Ivan Pustogarov Link: https://patch.msgid.link/20260903152616.1646637-1-ivan@ipust.net Signed-off-by: Johannes Berg --- include/linux/ieee80211-mesh.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ieee80211-mesh.h b/include/linux/ieee80211-mesh.h index 7eb15834531c..9e548b9173df 100644 --- a/include/linux/ieee80211-mesh.h +++ b/include/linux/ieee80211-mesh.h @@ -361,8 +361,7 @@ ieee80211_mesh_hwmp_perr_get_rcode(const u8 *ie, u8 dst_idx) /* IEEE Std 802.11-2016 9.4.2.113 PREQ element */ static inline bool ieee80211_mesh_preq_size_ok(const u8 *pos, u8 elen) { - struct ieee80211_mesh_hwmp_preq_bottom *preq_elem_bottom = - ieee80211_mesh_hwmp_preq_get_bottom(pos); + struct ieee80211_mesh_hwmp_preq_bottom *preq_elem_bottom; u8 target_count; int needed; @@ -378,6 +377,7 @@ static inline bool ieee80211_mesh_preq_size_ok(const u8 *pos, u8 elen) if (elen < needed) return false; + preq_elem_bottom = ieee80211_mesh_hwmp_preq_get_bottom(pos); target_count = preq_elem_bottom->target_count; /* IEEE Std 802.11-2016 Table 14-10 to 14-16 */ if (target_count < 1) -- cgit v1.2.3 From 47a582b2b0e7bb5753e4803988e150a405b57f51 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 2 Sep 2026 20:26:11 -0700 Subject: ethtool: document that GRXCLSRLALL rule_cnt is a caller-provided limit Three drivers have shipped a get_rxnfc() which dumps its entire rule table into rule_locs, reading rule_cnt as "how many rules do I have" rather than "how many entries did the caller allocate". Nothing in the callback's documentation contradicted that reading. The distinction only matters because the ioctl lets an unprivileged caller pick rule_cnt directly, so getting it wrong is a heap overflow rather than a truncated dump. Reviewed-by: Joe Damato Link: https://patch.msgid.link/20260903032611.3000029-6-kuba@kernel.org Signed-off-by: Jakub Kicinski --- include/linux/ethtool.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 12683b5d125e..253600c0eccd 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -1057,6 +1057,12 @@ struct kernel_ethtool_ts_info { * @get_sset_count: Get number of strings that @get_strings will write. * @get_rxnfc: Get RX flow classification rules. Returns a negative * error code or zero. + * Note that for %ETHTOOL_GRXCLSRLALL rule_cnt and size of the arrays + * is user-provided, and not guaranteed to match what driver would + * have reported via %ETHTOOL_GRXCLSRLCNT. Drivers must return -%EMSGSIZE + * when rule_cnt is too small. rule_locs is %NULL when rule_cnt is zero. + * On success drivers must set rule_cnt to the number of locations they + * filled in, the core copies out exactly that many. * @set_rxnfc: Set RX flow classification rules. Returns a negative * error code or zero. * @flash_device: Write a firmware image to device's flash memory. -- cgit v1.2.3 From 954f7a48fa2ae7310c67729fb556caf726783436 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 5 Sep 2026 10:43:57 +0200 Subject: entry: Guard syscall_enter_audit() invocation with CONFIG_AUDITSYSCALL A bunch of older cross compilers notably RISCV64 and S390 fail to eliminate the dead code when CONFIG_AUDITSYSCALL=n. The code in question is: if (unlikely(audit_context()) syscall_enter_audit(regs); and in case of CONFIG_AUDITSYSCALL=n: static inline struct audit_context *audit_context(void) { return NULL; } which should make the compiler eliminate the syscall_enter_audit() call. But a RISV64 GCC12 cross compiler translates that into: if (unlikely(audit_context())) 1c34: 00000097 auipc ra,0x0 1c38: 000080e7 jalr ra # 1c34 <.L785> 1c3c: c511 beqz a0,1c48 <.L787> syscall_enter_audit(regs); 1c3e: 8526 mv a0,s1 1c40: 00000097 auipc ra,0x0 1c44: 000080e7 jalr ra # 1c40 <.L785+0xc> and then claims in the failing link: include/asm-generic/preempt.h:54:(.noinstr.text+0x1a20): undefined reference to 'syscall_enter_audit' which is obviously hallucination. Add an explicit IS_ENABLED(CONFIG_AUDITSYSCALL) check into the condition to cure this compiler madness. Fixes: 6f25517010dd ("entry: Rework syscall_audit_enter()") Reported-by: kernel test robot Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://patch.msgid.link/87tso45bqq.ffs@fw13 Closes: https://lore.kernel.org/oe-kbuild-all/202609031938.ZvZZaRQy-lkp@intel.com/ --- include/linux/entry-common.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index 6574b7183c01..fa2854fed1f2 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -102,7 +102,14 @@ static __always_inline long syscall_trace_enter(struct pt_regs *regs, unsigned l if (unlikely(work & SYSCALL_WORK_SYSCALL_TRACEPOINT)) trace_syscall_enter(regs); - if (unlikely(audit_context())) + /* + * The config check works around broken compilers which fail to + * eliminate the dead code in case of CONFIG_AUDITSYSCALL=n as they + * insist on creating a always false runtime condition based on + * audit_context() which returns NULL in that case. The explicit + * IS_ENABLED() check makes that madness go away. + */ + if (IS_ENABLED(CONFIG_AUDITSYSCALL) && unlikely(audit_context())) syscall_enter_audit(regs); return true; -- cgit v1.2.3 From 0bd7ed1a3263c26cf38fffc035b539a70d88667b Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 25 Aug 2026 12:28:36 +0200 Subject: netfilter: arp_tables: remove the 32bit compat interface This feature is required to use 32bit arptables binary on 64bit kernels. It's already off in many distributions including Debian and Fedora for many years. Zap arptables first, it's the most esoteric of the 4 flavors. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter_arp/arp_tables.h | 19 ------------------- 1 file changed, 19 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netfilter_arp/arp_tables.h b/include/linux/netfilter_arp/arp_tables.h index 05631a25e622..8b8d472eff34 100644 --- a/include/linux/netfilter_arp/arp_tables.h +++ b/include/linux/netfilter_arp/arp_tables.h @@ -56,23 +56,4 @@ void arpt_unregister_table(struct net *net, const char *name); extern unsigned int arpt_do_table(void *priv, struct sk_buff *skb, const struct nf_hook_state *state); -#ifdef CONFIG_NETFILTER_XTABLES_COMPAT -#include - -struct compat_arpt_entry { - struct arpt_arp arp; - __u16 target_offset; - __u16 next_offset; - compat_uint_t comefrom; - struct compat_xt_counters counters; - unsigned char elems[]; -}; - -static inline struct xt_entry_target * -compat_arpt_get_target(struct compat_arpt_entry *e) -{ - return (void *)e + e->target_offset; -} - -#endif /* CONFIG_COMPAT */ #endif /* _ARPTABLES_H */ -- cgit v1.2.3 From a1c7570cedd03372812a5b693732880867babbca Mon Sep 17 00:00:00 2001 From: "Lorenzo Stoakes (ARM)" Date: Thu, 13 Aug 2026 12:01:24 +0300 Subject: x86/mm/pat: Acquire init_mm write lock on collapse to avoid UAF x86 implements page attribute modification using its Change Page Attributes (CPA) mechanism. This tracks properties of ranges such as cache mode through x86 page attributes, and as part of that logic manipulates kernel page tables. Since commit: 41d88484c71c ("x86/mm/pat: restore large ROX pages after fragmentation") ranges of kernel page table entries can be collapsed into huge page table entries as part of this logic. As part of this collapse, it frees the page tables which the collapsed entries previously pointed to, and it does so without any relevant locks being held to preclude concurrent kernel page table walkers. The only way this code can be reached is if CPA_COLLAPSE is specified, and this is only set in set_memory_rox() via: set_memory_rox() -> change_page_attr_set_clr() -> cpa_flush() -> cpa_collapse_large_pages() Notable users of this are execmem and BPF when manipulating executable mappings. However, this is problematic for ptdump as it walks ranges it does not own and thus runs the risk of a use-after-free on page tables freed underneath it. In addition, concurrent CPA collapse operations are possible which can also cause races. Resolve the issue by acquiring the mmap write lock on init_mm across the whole operation. It is safe to acquire a sleeping lock as all the callers invoke set_memory_rox() from process context and in any case, change_page_attr_set_clr() calls vm_unmap_alias() which ultimately takes a mutex, disallowing atomic context here. Fixes: 41d88484c71c ("x86/mm/pat: restore large ROX pages after fragmentation") Signed-off-by: Lorenzo Stoakes (ARM) Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Dave Hansen Signed-off-by: Ingo Molnar Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Kiryl Shutsemau (Meta) Reviewed-by: David Hildenbrand (Arm) Reviewed-by: Dave Hansen Reviewed-by: Will Deacon Reviewed-by: David Carlier Tested-by: Atish Patra Tested-by: Nikunj A Dadhania Cc:stable@vger.kernel.org Link: https://patch.msgid.link/20260813-cpa-fixes-v2-1-39b4ff90f91d@kernel.org --- include/linux/mmap_lock.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h index bec0eab6ef03..b8a13b8d36a4 100644 --- a/include/linux/mmap_lock.h +++ b/include/linux/mmap_lock.h @@ -630,6 +630,8 @@ static inline void mmap_read_unlock(struct mm_struct *mm) DEFINE_GUARD(mmap_read_lock, struct mm_struct *, mmap_read_lock(_T), mmap_read_unlock(_T)) DEFINE_GUARD_COND(mmap_read_lock, _try, mmap_read_trylock(_T)) +DEFINE_GUARD(mmap_write_lock, struct mm_struct *, + mmap_write_lock(_T), mmap_write_unlock(_T)) static inline void mmap_read_unlock_non_owner(struct mm_struct *mm) { -- cgit v1.2.3 From 51b0e68cfa0ac69e3c3ea9d6753af7e15dfaab22 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Wed, 9 Sep 2026 17:05:22 +0200 Subject: sched/eevdf: Fix rb augmented with multi fields The eevdf rb tree maintains 3 augmented fields but only one is currently copied when balancing the tree. Add a more generic define that can be used when there are several augmented fields. In this case, we provide a function that takes care of copying all fields. Fixes: aef6987d8954 ("sched/eevdf: Propagate min_slice up the cgroup hierarchy") Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: K Prateek Nayak Tested-by: K Prateek Nayak Link: https://patch.msgid.link/20260909150522.858312-1-vincent.guittot@linaro.org --- include/linux/rbtree_augmented.h | 35 ++++++++++++++++++++++++++++------- 1 file changed, 28 insertions(+), 7 deletions(-) (limited to 'include/linux') diff --git a/include/linux/rbtree_augmented.h b/include/linux/rbtree_augmented.h index 6dbc5a1bf6a8..d2fa1c41bfd2 100644 --- a/include/linux/rbtree_augmented.h +++ b/include/linux/rbtree_augmented.h @@ -87,18 +87,18 @@ rb_add_augmented_cached(struct rb_node *node, struct rb_root_cached *tree, } /* - * Template for declaring augmented rbtree callbacks (generic case) + * Template for declaring augmented rbtree callbacks (generic multi fields) * * RBSTATIC: 'static' or empty * RBNAME: name of the rb_augment_callbacks structure * RBSTRUCT: struct type of the tree nodes * RBFIELD: name of struct rb_node field within RBSTRUCT - * RBAUGMENTED: name of field within RBSTRUCT holding data for subtree - * RBCOMPUTE: name of function that recomputes the RBAUGMENTED data + * RBCOPY: name of function that copies the RBAUGMENTED datas + * RBCOMPUTE: name of function that recomputes the RBAUGMENTED datas */ -#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ - RBSTRUCT, RBFIELD, RBAUGMENTED, RBCOMPUTE) \ +#define RB_DECLARE_CALLBACKS_MULTI(RBSTATIC, RBNAME, \ + RBSTRUCT, RBFIELD, RBCOPY, RBCOMPUTE) \ static inline void \ RBNAME ## _propagate(struct rb_node *rb, struct rb_node *stop) \ { \ @@ -114,14 +114,14 @@ RBNAME ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \ { \ RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \ RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \ - new->RBAUGMENTED = old->RBAUGMENTED; \ + RBCOPY(new, old); \ } \ static void \ RBNAME ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \ { \ RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \ RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \ - new->RBAUGMENTED = old->RBAUGMENTED; \ + RBCOPY(new, old); \ RBCOMPUTE(old, false); \ } \ RBSTATIC const struct rb_augment_callbacks RBNAME = { \ @@ -130,6 +130,27 @@ RBSTATIC const struct rb_augment_callbacks RBNAME = { \ .rotate = RBNAME ## _rotate \ }; +/* + * Template for declaring augmented rbtree callbacks (generic single field) + * + * RBSTATIC: 'static' or empty + * RBNAME: name of the rb_augment_callbacks structure + * RBSTRUCT: struct type of the tree nodes + * RBFIELD: name of struct rb_node field within RBSTRUCT + * RBAUGMENTED: name of field within RBSTRUCT holding data for subtree + * RBCOMPUTE: name of function that recomputes the RBAUGMENTED data + */ + +#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ + RBSTRUCT, RBFIELD, RBAUGMENTED, RBCOMPUTE) \ +static inline void \ +RBNAME ## _copy_single(RBSTRUCT *new, RBSTRUCT *old) \ +{ \ + new->RBAUGMENTED = old->RBAUGMENTED; \ +} \ +RB_DECLARE_CALLBACKS_MULTI(RBSTATIC, RBNAME, \ + RBSTRUCT, RBFIELD, RBNAME ## _copy_single, RBCOMPUTE) + /* * Template for declaring augmented rbtree callbacks, * computing RBAUGMENTED scalar as max(RBCOMPUTE(node)) for all subtree nodes. -- cgit v1.2.3 From 88ce88e933e40f4ab4b81a5e9d0a10328583f593 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Thu, 10 Sep 2026 23:35:07 +0200 Subject: bpf: Add KF_PERFMON kfunc flag Tracing related BPF helpers e.g. under bpf_base_func_proto() are gated behind CAP_PERFMON. However, the same is currently not true for kfuncs and they are accessible via plain CAP_BPF. Add a new KF_PERFMON flag which can be used such that check_kfunc_call() ensures env->allow_ptr_leaks is permitted. This follows similar pattern to existing KF_DESTRUCTIVE flag. The rejection returns -EPERM to match the other CAP_PERFMON gates in the verifier, that is, check_ptr_to_btf_access() and check_ptr_to_map_access(), which report the very same policy to user space. Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/r/20260910213510.49358-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov --- include/linux/btf.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/btf.h b/include/linux/btf.h index 89d5a5c4f117..7c62ea17b116 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -80,6 +80,7 @@ #define KF_ARENA_ARG2 (1 << 15) /* kfunc takes an arena pointer as its second argument */ #define KF_IMPLICIT_ARGS (1 << 16) /* kfunc has implicit arguments supplied by the verifier */ #define KF_SPINLOCK_SAFE (1 << 17) /* kfunc is allowed inside bpf_spin_lock-ed region */ +#define KF_PERFMON (1 << 18) /* kfunc requires CAP_PERFMON */ /* * Tag marking a kernel function as a kfunc. This is meant to minimize the -- cgit v1.2.3 From 8cd280282d1239bca68f8c3632ef1ac8556a396b Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 6 Aug 2026 14:46:18 -0700 Subject: KVM: Never clear KVM_REQ_VM_DEAD from a vCPU's requests Use kvm_test_request() instead of kvm_check_request() when querying KVM_REQ_VM_DEAD, i.e. don't clear KVM_REQ_VM_DEAD, as the entire purpose of KVM_REQ_VM_DEAD is to prevent the vCPU from enterring the guest ever again, even if userspace insists on redoing KVM_RUN. Ensuring KVM_REQ_VM_DEAD is never cleared will allow relaxing KVM's rule that ioctls can't be invoked on dead VMs, to only disallow ioctls if the VM is bugged, i.e. if KVM hit a KVM_BUG_ON(). Opportunistically add compile-time assertions to guard against clearing KVM_REQ_VM_DEAD through the standard APIs. Reviewed-by: Kai Huang Acked-by: Marc Zyngier Link: https://patch.msgid.link/20260806214618.82180-1-seanjc@google.com Signed-off-by: Sean Christopherson --- include/linux/kvm_host.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 03bfc92864b6..cf7fe835c4ad 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2324,13 +2324,18 @@ static inline bool kvm_test_request(int req, struct kvm_vcpu *vcpu) return test_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests); } -static inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu) +static __always_inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu) { + BUILD_BUG_ON(req == KVM_REQ_VM_DEAD); + clear_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests); } -static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu) +static __always_inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu) { + /* Once a VM is dead, it needs to stay dead. */ + BUILD_BUG_ON(req == KVM_REQ_VM_DEAD); + if (kvm_test_request(req, vcpu)) { kvm_clear_request(req, vcpu); -- cgit v1.2.3 From 442ffa742daa65a0e8fe003abe9fbe472366e4de Mon Sep 17 00:00:00 2001 From: Vincent Donnefort Date: Fri, 11 Sep 2026 20:39:35 +0100 Subject: tracing/remotes: Account for ring buffer page header in size calculation trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the required pages because every ring buffer page contains a header (BUF_PAGE_HDR_SIZE). Account for that header to ensure allocated remote ring buffers aren't smaller than requested by the user. The newly introduced helper __calc_nr_pages_ring_buffer_desc() can return a value that overflows the descriptor nr_pages field (32 bits). Link: https://patch.msgid.link/20260911193937.602202-2-vdonnefort@google.com Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes") Signed-off-by: Vincent Donnefort Signed-off-by: Steven Rostedt --- include/linux/ring_buffer.h | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index afc7daa6ee7d..11bffb6a142d 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -3,8 +3,9 @@ #define _LINUX_RING_BUFFER_H #include -#include #include +#include +#include #include @@ -279,9 +280,19 @@ static inline struct ring_buffer_desc *__first_ring_buffer_desc(struct trace_buf return (struct ring_buffer_desc *)(&desc->__data[0]); } +/* + * Returns the number of pages for a ring_buffer_desc. The caller must ensure it + * does not overflow ring_buffer_desc::nr_page_va. + */ +static inline unsigned long __calc_nr_pages_ring_buffer_desc(size_t size) +{ + /* Takes into account the reader page */ + return max(DIV_ROUND_UP(size, PAGE_SIZE - BUF_PAGE_HDR_SIZE), 2UL) + 1; +} + static inline size_t trace_buffer_desc_size(size_t buffer_size, unsigned int nr_cpus) { - unsigned int nr_pages = max(DIV_ROUND_UP(buffer_size, PAGE_SIZE), 2UL) + 1; + unsigned long nr_pages = __calc_nr_pages_ring_buffer_desc(buffer_size); struct ring_buffer_desc *rbdesc; return size_add(offsetof(struct trace_buffer_desc, __data), -- cgit v1.2.3 From d059d8bf2c9b5d563d15e7552d73e17d7535013a Mon Sep 17 00:00:00 2001 From: Vincent Donnefort Date: Fri, 11 Sep 2026 20:39:36 +0100 Subject: tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. Return SIZE_MAX from trace_buffer_desc_size() on nr_page_va overflow. Link: https://patch.msgid.link/20260911193937.602202-3-vdonnefort@google.com Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes") Signed-off-by: Vincent Donnefort Signed-off-by: Steven Rostedt --- include/linux/ring_buffer.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index 11bffb6a142d..eac3e9080c3c 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -295,6 +295,10 @@ static inline size_t trace_buffer_desc_size(size_t buffer_size, unsigned int nr_ unsigned long nr_pages = __calc_nr_pages_ring_buffer_desc(buffer_size); struct ring_buffer_desc *rbdesc; + /* Capped by ring_buffer_desc::nr_page_va */ + if (nr_pages > UINT_MAX) + return SIZE_MAX; + return size_add(offsetof(struct trace_buffer_desc, __data), size_mul(nr_cpus, struct_size(rbdesc, page_va, nr_pages))); } -- cgit v1.2.3 From 3ed11c671ff7ec58c8fd96410233c677df23f407 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christian=20K=C3=B6nig?= Date: Fri, 4 Sep 2026 10:26:13 +0200 Subject: dma-buf/dma-fence: fix checking signaling bit for timeline and driver name v3 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch "dma-buf: dma-fence: Fix potential NULL pointer dereference" changed the check to test for the ops pointer instead of the signaled bit to avoid a potential NULL dereference when the ops pointer has been cleared. The problem is now that the ops pointer is cleared only when neither the release nor the wait callback is implemented and this isn't true for a lot of dma_fence implementations yet. So those implementations lost the RCU protection after signaling of the returned string resulting in potential use after free. Add the signaling check additional to the ops pointer check so that we have both the protection against NULL dereference as well as the RCU protection after signaling for the returned string. v2: improve comments to note RCU protection and explain why we check both signaling state and ops pointer v3: some comment improvements suggested by Philip Signed-off-by: Christian König Fixes: 035219a760ed ("dma-buf: dma-fence: Fix potential NULL pointer dereference") CC: stable@vger.kernel.org # 7.2+ Reported-by: Jonghyuk Kim(MalHyuk) Tested-by: Jonghyuk Kim(MalHyuk) Reviewed-by: Philipp Stanner Link: https://lore.kernel.org/r/20260914182740.1587-1-christian.koenig@amd.com --- include/linux/dma-fence.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 158cd609f103..ffa99b930843 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -141,6 +141,9 @@ struct dma_fence_ops { * compute the name at runtime, without having it to store permanently * for each fence, or build a cache of some sort. * + * The returned string is RCU protected and can be freed after the fence + * signaled and a RCU grace period passed. + * * This callback is mandatory. */ const char * (*get_driver_name)(struct dma_fence *fence); @@ -153,6 +156,9 @@ struct dma_fence_ops { * having it to store permanently for each fence, or build a cache of * some sort. * + * The returned string is RCU protected and can be freed after the fence + * signaled and a RCU grace period passed. + * * This callback is mandatory. */ const char * (*get_timeline_name)(struct dma_fence *fence); -- cgit v1.2.3 From 40c2096961b4e8f48d1fc17406a90c5a36ac0a8d Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Mon, 14 Sep 2026 15:19:20 +0200 Subject: bpf: Verify global subprogs in each sleepability context Global subprograms are verified independently with a fresh verifier root. do_check_common() currently seeds that root's in_sleepable state from the program, even though a global subprogram can also run from callbacks whose execution context differs from the program's main entry point. In particular, workqueue and task-work callbacks are sleepable even when the containing program is not. A global subprogram of that program is therefore verified as non-sleepable, making in_rcu_cs() true and allowing loads of RCU-protected kptrs to produce trusted MEM_RCU pointers. The same subprogram can then be called from a sleepable callback without a classic RCU reader. It can retain such a pointer while the object is freed and use it after free. The verifier's execution-context predicates are complementary. A state is sleepable only when in_sleepable is set and no RCU, preemption, IRQ, or lock region is active. Each condition which prevents sleeping also provides RCU protection, while in_rcu_cs() treats a non-sleepable state as implicitly protected. Use this relationship to represent a global subprogram caller with only the result of in_sleepable_context(). A protected sleepable caller is normalized to in_sleepable=false at the independent verification root. This both prevents sleepable operations and makes in_rcu_cs() true without copying caller-owned lock state. Track only the contexts in which each global subprogram is actually reached. Verify it once if all reachable calls use the same context, and twice only if both sleepable and non-sleepable calls reach it. Calls found while verifying globals or asynchronous callbacks mark further contexts for checking. Repeat the existing subprogram walk until all called contexts have been verified; unreachable global calls remain unchecked. Accumulate instruction counts over those verification passes. Preserve the total recorded before each pass, since path accounting has already added this pass's synchronous instructions and its root total must also include asynchronous subprograms. This makes an unprotected callback verify the global subprogram as sleepable, turning its RCU-protected kptr load into an untrusted pointer. Protected callers and global subprograms which do not depend on implicit RCU protection remain valid. Fixes: 81f1d7a583fa ("bpf: wq: add bpf_wq_set_callback_impl") Fixes: 38aa7003e369 ("bpf: task work scheduling kfuncs") Reported-by: Nicholas Carlini Suggested-by: Nicholas Carlini Signed-off-by: Kumar Kartikeya Dwivedi Acked-by: Eduard Zingerman Link: https://patch.msgid.link/20260914131923.2544250-2-memxor@gmail.com Signed-off-by: Eduard Zingerman --- include/linux/bpf.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index e57af902560c..1d2676782d70 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1651,8 +1651,9 @@ static inline void bpf_trampoline_set_flags(struct bpf_trampoline *tr, u32 flags struct bpf_func_info_aux { u16 linkage; bool unreliable; - bool called : 1; - bool verified : 1; + /* Indexed by in_sleepable. */ + bool called[2]; + bool verified[2]; }; enum bpf_jit_poke_reason { -- cgit v1.2.3 From c26e97721b172163042b98572fead234797f2c3c Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 18 Sep 2026 01:32:12 +0200 Subject: bpf: Apply CO-RE relocations before subprogram validation check_subprogs() verifies that each subprogram ends in an exit or an unconditional jump before in-kernel CO-RE relocations are applied. An unresolved relocation can then replace that terminal instruction with an invalid helper call. The resulting fall-through into another subprogram breaks the CFG invariant used by postorder and stack liveness analysis, which can write past their per-subprogram arrays. Apply CO-RE relocations immediately after preparing the program BTF, before subprogram discovery and validation. Keep func_info and line_info validation after subprogram discovery because those records depend on the complete subprogram layout. Reject an ldimm64 first slot at the end of the instruction stream before CO-RE can inspect its missing second slot. check_subprogs() previously rejected this form before relocation processing because it is not a valid subprogram terminator. Moving CO-RE ahead of check_subprogs() removes that implicit protection, so perform an explicit check before applying relocations. Include core_relo_cnt when deciding whether to prepare program BTF. A load that supplied only CO-RE relocation metadata previously skipped both BTF setup and relocation processing. Fixes: fbd94c7afcf9 ("bpf: Pass a set of bpf_core_relo-s to prog_load command.") Suggested-by: Andrii Nakryiko Suggested-by: Alexei Starovoitov Suggested-by: Eduard Zingerman Signed-off-by: Kumar Kartikeya Dwivedi Acked-by: Eduard Zingerman Link: https://patch.msgid.link/20260917233222.2542500-5-memxor@gmail.com Signed-off-by: Eduard Zingerman --- include/linux/bpf_verifier.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 36b65797877d..bba5a727c651 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -1197,6 +1197,8 @@ static inline void bpf_trampoline_unpack_key(u64 key, u32 *obj_id, u32 *btf_id) int bpf_prepare_btf_info(struct bpf_verifier_env *env, const union bpf_attr *attr, bpfptr_t uattr); +int bpf_check_core_relo(struct bpf_verifier_env *env, + const union bpf_attr *attr, bpfptr_t uattr); int bpf_check_btf_info(struct bpf_verifier_env *env, const union bpf_attr *attr, bpfptr_t uattr); -- cgit v1.2.3 From 71919742c83c32afcccf06a7a28e28f3f55f21a2 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 18 Sep 2026 01:32:16 +0200 Subject: bpf: Assign lock identity to callback map values A nested bpf_for_each_map_elem() callback can unlock a different element of the same map: static long inner(void *map, int *key, struct value *v, struct value **outer_value) { bpf_spin_lock(&v->lock); bpf_spin_unlock(&(*outer_value)->lock); return 0; } static long outer(void *map, int *key, struct value *v, void *ctx) { bpf_for_each_map_elem(map, inner, &v, 0); return 0; } Both callback values currently have ID zero and the same map_ptr. process_spin_lock() compares those two fields, so it accepts the unlock even though the two callbacks can receive different map elements. Assign a fresh ID to every callback map value in the for-each, timer/workqueue, and task-work constructors. Copies of one callback argument retain its ID, so locking and unlocking through that argument continues to work. Distinct callbacks also get distinct IDs for single-element arrays, including inner arrays sharing inner_map_meta. Preserve map_uid for every inner-map lookup and compare it through check_ids() during state pruning. This preserves relationships between maps, keys, and values while allowing equivalent states with different lookup IDs to match. It avoids field-specific rules for when an inner map needs an identity. Move map_uid out of the metadata union and next to the other IDs, so register comparisons can use the existing memcmp() ranges and remap the IDs separately. Clear it when resetting a register or converting a map lookup result to a socket pointer. Shrink frameno to u8, which is enough for MAX_CALL_FRAMES, to make room without growing bpf_reg_state. Fixes: d0d78c1df9b1 ("bpf: Allow locking bpf_spin_lock global variables") Reported-by: Nicholas Carlini Suggested-by: Nicholas Carlini Signed-off-by: Kumar Kartikeya Dwivedi Acked-by: Eduard Zingerman Link: https://patch.msgid.link/20260917233222.2542500-9-memxor@gmail.com Signed-off-by: Eduard Zingerman --- include/linux/bpf_verifier.h | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index bba5a727c651..a7202b44ab10 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -46,17 +46,11 @@ struct bpf_reg_state { /* valid when type == PTR_TO_PACKET */ int range; - /* valid when type == CONST_PTR_TO_MAP | PTR_TO_MAP_VALUE | - * PTR_TO_MAP_VALUE_OR_NULL + /* + * For CONST_PTR_TO_MAP, PTR_TO_MAP_KEY, PTR_TO_MAP_VALUE and + * PTR_TO_INSN. */ - struct { - struct bpf_map *map_ptr; - /* To distinguish map lookups from outer map - * the map_uid is non-zero for registers - * pointing to inner maps. - */ - u32 map_uid; - }; + struct bpf_map *map_ptr; /* for PTR_TO_BTF_ID */ struct { @@ -155,13 +149,20 @@ struct bpf_reg_state { * gets parent_id set to the dynptr's id. */ u32 parent_id; - /* Inside the callee two registers can be both PTR_TO_STACK like + /* + * Distinguishes inner-map lookups and their keys and values. Zero for + * other registers. Kept outside the metadata union for ID remapping + * during state comparisons. + */ + u32 map_uid; + /* + * Inside the callee two registers can be both PTR_TO_STACK like * R1=fp-8 and R2=fp-8, but one of them points to this function stack * while another to the caller's stack. To differentiate them 'frameno' * is used which is an index in bpf_verifier_state->frame[] array * pointing to bpf_func_state. */ - u32 frameno; + u8 frameno; /* if (!precise && SCALAR_VALUE) min/max/tnum don't affect safety */ bool precise; }; -- cgit v1.2.3 From 1b82958f3f035df5ccaab5430a2302f08a5d5351 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Mon, 14 Sep 2026 14:09:57 -0700 Subject: net: ethtool: keep rtnl_lock for the ioctl self test An offline self test that brings the interface down and back up with netif_close() / netif_open() requires rtnl_lock for both. Since the ethtool IOCTL path became rtnl-optional for ops-locked drivers, the ETHTOOL_TEST ioctl runs holding only the netdev instance lock, so on an ops-locked driver the self test now tears the device down without rtnl_lock. With lockdep this reproduces deterministically on every offline self test on such a driver; note the sole lock held is the instance lock, not rtnl: WARNING: suspicious RCU usage net/core/netpoll.c:207 suspicious rcu_dereference_protected() usage! 1 lock held by ethtool/107: #0: (&dev->lock){+.+.}, at: dev_ethtool Call Trace: netpoll_poll_disable __dev_close_many netif_close_many netif_close fbnic_self_test dev_ethtool_locked dev_ethtool dev_ioctl sock_ioctl __x64_sys_ioctl Without lockdep the same condition trips ASSERT_RTNL() in __dev_close_many() / __dev_open(); that check only samples the global rtnl state, so it can be masked by a concurrent rtnl holder, but the device is still being reconfigured without the lock it requires. The ethtool self_test is a legacy ioctl-only command, so an ETHTOOL_TEST case is only needed on the ioctl path. Add an opt-in bit for drivers whose self test needs rtnl_lock and set it on the ops-locked drivers whose offline self test tears the interface down and up: - fbnic (ops-locked via queue_mgmt_ops): fbnic_self_test() offline path uses netif_close() / netif_open(). - bnxt (ops-locked via queue_mgmt_ops): bnxt_self_test() offline path goes through bnxt_close_nic() / bnxt_half_open_nic() / bnxt_half_close_nic() / bnxt_open_nic(), which close and reopen the device. Fixes: f994752b1127 ("net: ethtool: optionally skip rtnl_lock on IOCTL path") Signed-off-by: Alexander Duyck Reviewed-by: Simon Horman Link: https://patch.msgid.link/178942019771.7700.338431553546884773.stgit@ahduyck-xeon-server.home.arpa Signed-off-by: Jakub Kicinski --- include/linux/ethtool.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 253600c0eccd..c4c9ce038611 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -944,6 +944,7 @@ struct kernel_ethtool_ts_info { #define ETHTOOL_OP_NEEDS_RTNL_SPAUSEPARAM BIT(6) #define ETHTOOL_OP_NEEDS_RTNL_RSS BIT(7) #define ETHTOOL_OP_NEEDS_RTNL_GLINK BIT(8) +#define ETHTOOL_OP_NEEDS_RTNL_TEST BIT(9) /** * struct ethtool_ops - optional netdev operations @@ -981,6 +982,7 @@ struct kernel_ethtool_ts_info { * - netdev_update_features() * - netif_set_real_num_tx_queues() * - ethtool_op_get_link() (syncs link watch under rtnl_lock) + * - netif_open() / netif_close() (used by @self_test) * * @get_drvinfo: Report driver/device information. Modern drivers no * longer have to implement this callback. Most fields are -- cgit v1.2.3 From 8901cee9316d53a5a97398f026c2d59a3043159d Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Sat, 19 Sep 2026 03:42:10 +0200 Subject: bpf: Compare stack frames in regs_exact() regs_exact() compares the register state up to id, followed by the ID mappings, but does not compare frameno. The PTR_TO_STACK case in regsafe() checks frameno separately, which is bypassed when exact comparison is requested. Consequently, infinite-loop detection can treat pointers to different stack frames as the same pointer and reject a finite loop. For example, initialize fp-8 to zero in the caller and to one in the callee, then pass the caller's fp-8 to the callee as r1: loop: r0 = *(u64 *)(r1 + 0); if r0 != 0 goto done; r1 = r10; r1 += -8; goto loop; done: exit; The loop terminates after reading the callee's slot on its second iteration. At the loop header, however, the only relevant difference is r1's frameno, so exact comparison incorrectly reports an infinite loop. The same problem occurs when the pointer is spilled to the stack. Move frameno into the type-specific metadata union, ahead of id, so the existing prefix comparison in regs_exact() covers it. Ordinary stack pointers do not use another union member. Iterator and IRQ stack-slot states use their dedicated union views and do not need a frame lookup. This also keeps bpf_reg_state at 80 bytes. Since frameno now shares storage with other pointer metadata, it is only meaningful for PTR_TO_STACK registers. Return NULL from bpf_func() for other register types. process_iter_arg(), get_constant_map_key() and is_dynptr_reg_valid_init() look up the frame before checking the register type and would otherwise index frame[] with a byte of the register's map or BTF pointer. They dereference the frame only after their type check. Move the states_maybe_looping() boundary from frameno to precise after the field relocation. Its prefix comparison continues to cover the complete value state and now includes frameno. Continue to ignore precise. Precision marks control whether pruning may ignore scalar ranges; they do not change the represented values, and exact comparison already compares those ranges unconditionally. Marks can also change through backtracking while an ancestor state is still being explored. Fixes: d5b892fd607a ("bpf: make infinite loop detection in is_state_visited() exact") Reported-by: Eduard Zingerman Signed-off-by: Kumar Kartikeya Dwivedi Signed-off-by: Alexei Starovoitov Acked-by: Eduard Zingerman Link: https://patch.msgid.link/20260919014213.1840880-2-memxor@gmail.com --- include/linux/bpf_verifier.h | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index a7202b44ab10..6fe8e5dc57aa 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -45,6 +45,14 @@ struct bpf_reg_state { union { /* valid when type == PTR_TO_PACKET */ int range; + /* + * Valid when type == PTR_TO_STACK. Inside the callee two registers + * can be both PTR_TO_STACK like R1=fp-8 and R2=fp-8, but one of them + * points to this function stack while another to the caller's stack. + * To differentiate them 'frameno' is used which is an index in + * bpf_verifier_state->frame[] array pointing to bpf_func_state. + */ + u8 frameno; /* * For CONST_PTR_TO_MAP, PTR_TO_MAP_KEY, PTR_TO_MAP_VALUE and @@ -155,14 +163,6 @@ struct bpf_reg_state { * during state comparisons. */ u32 map_uid; - /* - * Inside the callee two registers can be both PTR_TO_STACK like - * R1=fp-8 and R2=fp-8, but one of them points to this function stack - * while another to the caller's stack. To differentiate them 'frameno' - * is used which is an index in bpf_verifier_state->frame[] array - * pointing to bpf_func_state. - */ - u8 frameno; /* if (!precise && SCALAR_VALUE) min/max/tnum don't affect safety */ bool precise; }; @@ -1239,11 +1239,18 @@ static inline int bpf_get_spi(s32 off) return (-off - 1) / BPF_REG_SIZE; } +/* + * Return the function state a stack pointer register refers to. frameno + * shares storage with other pointer metadata, so return NULL for any + * other register type instead of indexing frame[] with aliased bytes. + */ static inline struct bpf_func_state *bpf_func(struct bpf_verifier_env *env, const struct bpf_reg_state *reg) { struct bpf_verifier_state *cur = env->cur_state; + if (reg->type != PTR_TO_STACK) + return NULL; return cur->frame[reg->frameno]; } -- cgit v1.2.3 From ab888242fce4f16f6c4d4c6ec53939ad36aa3b3a Mon Sep 17 00:00:00 2001 From: Xiang Mei Date: Tue, 15 Sep 2026 01:31:52 -0700 Subject: vlan: require the MAC header to be present in __vlan_insert_inner_tag() __vlan_insert_inner_tag() only guarantees head room via skb_cow_head(), never that mac_len bytes of MAC header are present. Its ETH_HLEN wrappers - __vlan_insert_tag() under skb_vlan_push(), and vlan_insert_tag() under validate_xmit_vlan() on the generic transmit path - therefore rewrite the first 16 bytes at skb->data: a 12-byte memmove plus two 2-byte stores at +12 and +14. No caller supplies the bound, while the pop helpers use skb_ensure_writable()/pskb_may_pull(). An IFF_TUN device has hard_header_len == 0, so packet_snd() accepts a one-byte AF_PACKET/SOCK_RAW frame. The first vlan push only sets a hwaccel tag; the next - clsact "action vlan push" or bpf_skb_vlan_push() - enters the helper with skb->len still 1. The head comes from skbuff_small_head without __GFP_ZERO, so each push drags bytes from beyond skb->tail into the frame. After three the one-byte send leaves as 13 bytes carrying 11 bytes of uninitialised slab: 0000: 5a b3 62 12 80 88 ff ff 00 b3 62 12 81 `------------------------------' only 0x5a was sent; the rest is slab, here the top 56 bits of a linear-map address Require the MAC header the helper rewrites to be present, so such a frame is dropped rather than transmitted. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: co+0ea1ac045375cf05@bugs.sh Signed-off-by: Xiang Mei Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260915083152.705309-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski --- include/linux/if_vlan.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 20cc16ea4e5a..4846032bf4ff 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -365,6 +365,9 @@ static inline int __vlan_insert_inner_tag(struct sk_buff *skb, const u8 meta_len = mac_len > ETH_TLEN ? skb_metadata_len(skb) : 0; struct vlan_ethhdr *veth; + if (unlikely(!pskb_may_pull(skb, mac_len))) + return -EINVAL; + if (skb_cow_head(skb, meta_len + VLAN_HLEN) < 0) return -ENOMEM; -- cgit v1.2.3 From e6bae5034ef4a61f3f062b18140d4f58c8b9a149 Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Fri, 18 Sep 2026 14:40:32 +0200 Subject: ata: libata-core: Extend Samsung LPM quirk to AMD controllers A Samsung SSD 870 QVO 8TB connected to an AMD 600 Series chipset SATA controller is reported to time out on STANDBY IMMEDIATE during system suspend with med_power_with_dipm enabled. The command completes when using max_performance instead. The existing Samsung LPM quirk only matches ATI controllers, leaving AMD controllers unaffected. Rename it to ATA_QUIRK_NO_LPM_ON_ATI_AND_AMD and extend the vendor check to AMD for the same Samsung SSD model patterns. Keep LPM behavior unchanged for other controller vendors, including Intel. Leave ATA_QUIRK_NO_NCQ_ON_ATI restricted to ATI, since the reported AMD issue concerns LPM rather than NCQ. Link: https://bugzilla.kernel.org/show_bug.cgi?id=221986 Reviewed-by: Damien Le Moal Reviewed-by: Mario Limonciello (AMD) > --- Link: https://lore.kernel.org/r/20260918124030.1962773-5-cassel@kernel.org Signed-off-by: Niklas Cassel --- include/linux/libata.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/libata.h b/include/linux/libata.h index 313e96173b19..48bde275968d 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -76,7 +76,7 @@ enum ata_quirks { __ATA_QUIRK_MAX_SEC, /* Limit max sectors */ __ATA_QUIRK_MAX_TRIM_128M, /* Limit max trim size to 128M */ __ATA_QUIRK_NO_NCQ_ON_ATI, /* Disable NCQ on ATI chipset */ - __ATA_QUIRK_NO_LPM_ON_ATI, /* Disable LPM on ATI chipset */ + __ATA_QUIRK_NO_LPM_ON_ATI_AND_AMD, /* Disable LPM on ATI and AMD chipsets */ __ATA_QUIRK_NO_ID_DEV_LOG, /* Identify device log missing */ __ATA_QUIRK_NO_LOG_DIR, /* Do not read log directory */ __ATA_QUIRK_NO_FUA, /* Do not use FUA */ @@ -115,7 +115,7 @@ enum { ATA_QUIRK_MAX_SEC = BIT_ULL(__ATA_QUIRK_MAX_SEC), ATA_QUIRK_MAX_TRIM_128M = BIT_ULL(__ATA_QUIRK_MAX_TRIM_128M), ATA_QUIRK_NO_NCQ_ON_ATI = BIT_ULL(__ATA_QUIRK_NO_NCQ_ON_ATI), - ATA_QUIRK_NO_LPM_ON_ATI = BIT_ULL(__ATA_QUIRK_NO_LPM_ON_ATI), + ATA_QUIRK_NO_LPM_ON_ATI_AND_AMD = BIT_ULL(__ATA_QUIRK_NO_LPM_ON_ATI_AND_AMD), ATA_QUIRK_NO_ID_DEV_LOG = BIT_ULL(__ATA_QUIRK_NO_ID_DEV_LOG), ATA_QUIRK_NO_LOG_DIR = BIT_ULL(__ATA_QUIRK_NO_LOG_DIR), ATA_QUIRK_NO_FUA = BIT_ULL(__ATA_QUIRK_NO_FUA), -- cgit v1.2.3 From 28f9c0e0a0b94c5d3e1b634db545f6e1f94858c5 Mon Sep 17 00:00:00 2001 From: Tim Chen Date: Mon, 21 Sep 2026 17:37:24 -0700 Subject: sched/cache: Decouple sched_cache_group from mm to fix UAF Currently the sched cache grouping is by mm and the scheduling statistics sched_cache_stat lives in the mm structure. This ties the life cycle of scheduling stats with mm. In account_mm_sched(), the scheduling stats are accessed by task->mm->sc_stat. However, a task may be switching mm on one CPU when another CPU is running account_mm_sched(), and possibly accessing the old mm that was freed. This problem was found when running tests with KASAN by Hyunwoo: https://lore.kernel.org/lkml/apPb-Dr4nPYuHQOK@v4bel/ Instead of serializing the mm access by introducing extra acquisition of rq lock in the mm free path, extract sched_cache_stat from mm_struct, rename it as sched_cache_group and manage its life cycle apart from mm_struct with its own ref counting. This allows us in the next patch access sched_cache_group directly from task, and add a refcount on sched_cache_group when a task links to it. This prevents the use after free issue when accessing stale and released old mm and its sched cache stat a task switches to a new mm while account_mm_sched() is done elsewhere. The other benefit of this restructure is in the future, the grouping of tasks to a LLC would have the flexibility to be associated with a user defined grouping, or cgroup, cookie group, numa_group or others instead of just with a single mm address space. Rename sched_cache_stat to sched_cache_group and turn it into a refcounted object allocated from mm_struct. The mm_struct now holds a pointer (sched_cache_grp) to this object instead of embedding it. Fixes: df0d98475954 ("sched/cache: Introduce infrastructure for cache-aware load balancing") Closes: https://lore.kernel.org/lkml/apPb-Dr4nPYuHQOK@v4bel/ Closes: https://lore.kernel.org/all/343a7e07-7fad-4979-9c9b-82ec038c293c@linux.dev/ Reported-by: Hyunwoo Kim Reported-by: Zenghui Yu (Huawei) Co-developed-by: Chen Yu Signed-off-by: Chen Yu Signed-off-by: Tim Chen Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Cc: #7.2.x Link: https://patch.msgid.link/91fd1e3266707c865bc9abecfb3e17bc676712df.1790035273.git.tim.c.chen@linux.intel.com --- include/linux/mm_types.h | 15 +++++---------- include/linux/sched.h | 6 ++++-- 2 files changed, 9 insertions(+), 12 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 6d815f6440c9..f3e5a2fadbe5 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -1226,7 +1226,7 @@ struct mm_struct { struct mm_mm_cid mm_cid; /* sched_cache related statistics */ - struct sched_cache_stat sc_stat; + struct sched_cache_group *sched_cache_grp; #ifdef CONFIG_MMU atomic_long_t pgtables_bytes; /* size of all page tables */ #endif @@ -1624,8 +1624,9 @@ static inline unsigned int mm_cid_size(void) #endif /* CONFIG_SCHED_MM_CID */ #ifdef CONFIG_SCHED_CACHE -void mm_init_sched(struct mm_struct *mm, - struct sched_cache_time __percpu *pcpu_sched); +int mm_init_sched(struct mm_struct *mm, + struct sched_cache_time __percpu *pcpu_sched); +void mm_destroy_sched(struct mm_struct *mm); static inline int mm_alloc_sched_noprof(struct mm_struct *mm) { @@ -1635,17 +1636,11 @@ static inline int mm_alloc_sched_noprof(struct mm_struct *mm) if (!pcpu_sched) return -ENOMEM; - mm_init_sched(mm, pcpu_sched); - return 0; + return mm_init_sched(mm, pcpu_sched); } #define mm_alloc_sched(...) alloc_hooks(mm_alloc_sched_noprof(__VA_ARGS__)) -static inline void mm_destroy_sched(struct mm_struct *mm) -{ - free_percpu(mm->sc_stat.pcpu_sched); - mm->sc_stat.pcpu_sched = NULL; -} #else /* !CONFIG_SCHED_CACHE */ static inline int mm_alloc_sched(struct mm_struct *mm) { return 0; } diff --git a/include/linux/sched.h b/include/linux/sched.h index 705970d07614..e14ad43522c8 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2405,7 +2405,7 @@ struct sched_cache_time { unsigned long epoch; }; -struct sched_cache_stat { +struct sched_cache_group { struct sched_cache_time __percpu *pcpu_sched; raw_spinlock_t lock; unsigned long epoch; @@ -2413,11 +2413,13 @@ struct sched_cache_stat { unsigned long next_scan; unsigned long footprint; int cpu; + refcount_t refcnt; + struct rcu_head rcu; } ____cacheline_aligned_in_smp; #else -struct sched_cache_stat { }; +struct sched_cache_group { }; #endif -- cgit v1.2.3 From b636fef85bda7d1bab9c0a45067ab1508d79d946 Mon Sep 17 00:00:00 2001 From: Tim Chen Date: Mon, 21 Sep 2026 17:37:25 -0700 Subject: sched/cache: Introduce task_struct->sched_cache_grp to fix UAF Add a sched_cache_grp pointer to task_struct so that scheduler code can access the cache group directly via the task, without going through mm->sched_cache_grp. This decouples the scheduler's hot-path accesses from the mm_struct. Each task holds its own refcount on the sched_cache_group, separate from the reference held by its mm_struct. The reference is acquired in copy_mm() (fork) and exec_mmap() (exec), and released in exit_mm(). This fixes the use-after-free when account_mm_sched() reaches the group through a task whose mm is being switched, as reported by Hyunwoo: https://lore.kernel.org/lkml/apPb-Dr4nPYuHQOK@v4bel/ Convert all scheduler code in fair.c and exit.c to use p->sched_cache_grp instead of p->mm->sched_cache_grp. Keep the fork/exec/exit reference management out of the generic mm paths: add sched_cache_fork(), sched_cache_fork_cleanup(), sched_cache_exec_mmap() and sched_cache_exit_mm() in kernel/sched/cache_sched.c (with empty stubs for !CONFIG_SCHED_CACHE), so fs/exec.c, kernel/fork.c and kernel/exit.c each call one helper instead of open-coding the refcounting under #ifdef. Also add sched_cache_group_get() and task_cache_group_get(). Fixes: df0d98475954 ("sched/cache: Introduce infrastructure for cache-aware load balancing") Closes: https://lore.kernel.org/lkml/apPb-Dr4nPYuHQOK@v4bel/ Closes: https://lore.kernel.org/all/343a7e07-7fad-4979-9c9b-82ec038c293c@linux.dev/ Reported-by: Hyunwoo Kim Reported-by: Zenghui Yu (Huawei) Co-developed-by: Chen Yu Signed-off-by: Chen Yu Signed-off-by: Tim Chen Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Cc: #7.2.x Link: https://patch.msgid.link/ae7081dc54736bf115215f9867abb2711a7403fb.1790035273.git.tim.c.chen@linux.intel.com --- include/linux/sched.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux') diff --git a/include/linux/sched.h b/include/linux/sched.h index e14ad43522c8..d35ae49a991f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1433,6 +1433,7 @@ struct task_struct { #ifdef CONFIG_SCHED_CACHE struct callback_head cache_work; + struct sched_cache_group __rcu *sched_cache_grp; int preferred_llc; /* 1: task was enqueued to its preferred LLC, 0 otherwise */ int pref_llc_queued; @@ -2417,10 +2418,23 @@ struct sched_cache_group { struct rcu_head rcu; } ____cacheline_aligned_in_smp; +struct sched_cache_group *sched_cache_group_get(struct sched_cache_group *grp); +struct sched_cache_group *task_cache_group_get(struct task_struct *p); + +void sched_cache_fork(struct task_struct *p); +void sched_cache_fork_cleanup(struct task_struct *p); +void sched_cache_exec_mmap(struct task_struct *p, struct mm_struct *mm); +void sched_cache_exit_mm(struct task_struct *p); + #else struct sched_cache_group { }; +static inline void sched_cache_fork(struct task_struct *p) { } +static inline void sched_cache_fork_cleanup(struct task_struct *p) { } +static inline void sched_cache_exec_mmap(struct task_struct *p, struct mm_struct *mm) { } +static inline void sched_cache_exit_mm(struct task_struct *p) { } + #endif #ifndef MODULE -- cgit v1.2.3 From 3cb0243767fd033bdce95f4f1b5882172a2f8119 Mon Sep 17 00:00:00 2001 From: Davi Chaves Azevedo Date: Mon, 21 Sep 2026 17:37:27 -0700 Subject: sched/cache: Refresh LLC capacity across CPU hotplug, to fix capacity underestimation bug The scheduler scales LLC capacity by the fraction of cache-sharing CPUs covered by a domain: llc_bytes = cache_size * span_weight / shared_weight During CPU teardown, sched_cpu_deactivate() rebuilds scheduler domains before cacheinfo_cpu_pre_down() removes the CPU from shared_cpu_map. The new domains therefore use the old sharing weight. The later call to sched_update_llc_bytes() looks up the departing CPU's sd_llc, which has already been detached, and returns without correcting the surviving CPUs. On a Ryzen 5 7535U with twelve logical CPUs sharing a 16 MiB LLC, offlining one SMT sibling left the remaining CPUs with: llc_bytes = floor(16777216 * 11 / 12) = 15379114 bytes The correct capacity is still 16777216 bytes. On systems with active cache-aware scheduling, an underestimated capacity can cause exceed_llc_capacity() to reject aggregation for a process whose footprint would fit. Unchanged cpuset partitions sharing the physical cache can also retain stale capacity when a CPU comes online in another partition. Pass the cache-sharing mask already retained by cacheinfo to the scheduler update. Refresh every surviving CPU using its own LLC domain so that each partition receives the correct share. This also preserves the correction needed as cache-sharing maps grow during boot. Keep the existing CPU-hotplug and scheduler-domain synchronization. The update remains on the hotplug path; no steady-state scheduling operation or persistent allocation is added. Fixes: 7030513a0877 ("sched/cache: Calculate the LLC size and store it in sched_domain") Signed-off-by: Davi Chaves Azevedo Signed-off-by: Tim Chen Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Chen Yu Reviewed-by: Tim Chen Reviewed-by: K Prateek Nayak Tested-by: Chen Yu Tested-by: K Prateek Nayak Cc: # v7.2.x Link: https://patch.msgid.link/6751d93e15889e624796c74db0bfe66603d60b1b.1790035273.git.tim.c.chen@linux.intel.com --- include/linux/sched/topology.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index b5d9d7c2b8ad..f96812d71c51 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -281,9 +281,9 @@ static inline int task_node(const struct task_struct *p) } #ifdef CONFIG_SCHED_CACHE -extern void sched_update_llc_bytes(unsigned int cpu); +extern void sched_update_llc_bytes(const struct cpumask *cpus); #else -static inline void sched_update_llc_bytes(unsigned int cpu) { } +static inline void sched_update_llc_bytes(const struct cpumask *cpus) { } #endif #endif /* _LINUX_SCHED_TOPOLOGY_H */ -- cgit v1.2.3 From ed6eec97b534979dcf28b40c389cee57bd6561d4 Mon Sep 17 00:00:00 2001 From: Emil Tsalapatis Date: Tue, 22 Sep 2026 17:20:18 +0000 Subject: bpf: Fix bounds check for skb-backed dynptrs The skb_pointer_if_linear() function checks whether a memory region of length len starting at offset off into the skb is in the linear area, and returns a pointer to the region if so. The check currently subtracts between skb_headlen and offset of the check, and since skb_headlen is unsigned the subtraction can underflow. This causes the bounds check to spuriously pass and generate an arbitrary pointer of the form *(skb->data + off). The only user of this helper is currently skb-backed BPF dynptr code. Returning the wrong pointer leads to the dynptr erroneously being backed with invalid memory. Ensure the subtraction cannot underflow, and fail the check if it would. Use u64 arithmetic to also prevent overflow when calculating (skb_headlen(skb) - off) since off is unsigned. Fixes: 6f5a630d7c57 ("bpf, net: Introduce skb_pointer_if_linear().") Reported-by: Nicholas Carlini Signed-off-by: Emil Tsalapatis Signed-off-by: Alexei Starovoitov Reviewed-by: Jiayuan Chen Link: https://patch.msgid.link/20260922172028.6269-2-emil@etsalapatis.com --- include/linux/skbuff.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 421f6fc45451..c8e21903074c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -4372,7 +4372,10 @@ skb_header_pointer_careful(const struct sk_buff *skb, int offset, static inline void * __must_check skb_pointer_if_linear(const struct sk_buff *skb, int offset, int len) { - if (likely(skb_headlen(skb) - offset >= len)) + unsigned int uoffset = (unsigned int)offset; + + if (likely(uoffset <= skb_headlen(skb) && + (unsigned int)len <= skb_headlen(skb) - uoffset)) return skb->data + offset; return NULL; } -- cgit v1.2.3 From f85f5917aa2fbd861c72ea71ecb14a2fa915c3f6 Mon Sep 17 00:00:00 2001 From: Emil Tsalapatis Date: Tue, 22 Sep 2026 17:20:24 +0000 Subject: bpf: Prevent variable arena/non-arena register contents The verifier marks ALU instructions that include at least one arena operand with needs_zext: These instructions are fixed up after verification to be ALU32 instructions to ensure that the result is a valid offset into an arena. However, different code paths may provide two non-arena 64-bit arguments to the same instruction. The result of the operation in that code path is wrong, since it is now unexpectedly truncated to 32 bits and zero-extended. Add logic to the verifier to ensure every instruction either always has at least one PTR_TO_ARENA argument, or never does. Since needs_zext already tracks the first scenario, add a prevent_zext field in bpf_insn_aux to track the latter. Reject instructions that use arena arguments and have prevent_zext set, or do not have arena arguments and have needs_zext set. Fixes: 6082b6c328b5 ("bpf: Recognize addr_space_cast instruction in the verifier.") Reported-by: Nicholas Carlini Suggested-by: Nicholas Carlini Signed-off-by: Emil Tsalapatis Signed-off-by: Alexei Starovoitov Link: https://patch.msgid.link/20260922172028.6269-8-emil@etsalapatis.com --- include/linux/bpf_verifier.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 6fe8e5dc57aa..b83ec99f1a13 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -680,6 +680,7 @@ struct bpf_insn_aux_data { bool nospec_result; /* result is unsafe under speculation, nospec must follow */ bool zext_dst; /* this insn zero extends dst reg */ bool needs_zext; /* alu op needs to clear upper bits */ + bool prevent_zext; /* alu op cannot be zext (already used with 64-bit scalars) */ bool non_sleepable; /* helper/kfunc may be called from non-sleepable context */ bool is_iter_next; /* bpf_iter__next() kfunc call */ bool call_with_percpu_alloc_ptr; /* {this,per}_cpu_ptr() with prog percpu alloc */ -- cgit v1.2.3 From 9518405613863d0bf0700927a21367f5942cf058 Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Fri, 18 Sep 2026 20:47:29 -0400 Subject: packet: use ubuf_info completion for TX_RING packets tpacket_snd sends skbs with frags pointing into its ring slots. Slots are released when skb->destructor is called. A call to skb_orphan calls skb->destructor before the skb is freed. This can cause the slot to be reused while still linked into the skb. Switch to standard zerocopy completion (ubuf_info) so the slot is only released once all references to the payload are freed or copied. Restore skb->destructor to standard sock_wfree. The ubuf_info completion callback can be called with a NULL skb, but only from net_zcopy_put and related API, used by zerocopy implementations that hold their own reference on the uarg, such as MSG_ZEROCOPY. This uarg is only ever completed from skb_zcopy_clear, so skb is always set. To prevent userspace from aliasing in-flight state on shared ring slots, allocate tpacket_uarg per packet, rather than per slot. This adds a small allocation to the transmit path. Use standard kmalloc to allow backporting to stable kernels. The uarg holds an sk_wmem_alloc reference, rather than an sk_refcnt reference. packet_free_tx_ring waits on sk_wmem_alloc before freeing the ring pages. Always allocate vec->deferred for tx_ring so page-backed rings also wait on sk_wmem_alloc when skb_copy_ubufs drops page refs before calling tpacket_ubuf_complete. Drop the tx_ring.pg_vec test that tpacket_destruct_skb performed before accessing the slot. The sk_wmem_alloc reference now guarantees that the slot is valid. The test is also not sufficient by itself, as it reads pg_vec without pg_vec_lock, so it can race with packet_set_ring. As a result a slot is released when its payload is copied, which can be before transmission (e.g., in skb_orphan_frags_rx). If copied before skb_tx_timestamp() is called, no slot timestamp is recorded, similar to when skb_orphan() was called early in the datapath before this patch. Revert the now unused previous skb_zcopy_.._nouarg infra. Depends on commit 992cc9f94ca9 ("net/packet: defer vmalloc TX_RING free until skbs finish"). Reported-by: Katherine Leaver Reported-by: Bjoern Doebel Closes: https://lore.kernel.org/netdev/20260909085542.3370986-1-doebel@amazon.de/ Fixes: 5cd8d46ea156 ("packet: copy user buffers before orphan or clone") Cc: stable@vger.kernel.org Signed-off-by: Willem de Bruijn Link: https://patch.msgid.link/20260919004748.1463985-3-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski --- include/linux/skbuff.h | 19 +------------------ 1 file changed, 1 insertion(+), 18 deletions(-) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 421f6fc45451..b14d6be7370b 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1834,22 +1834,6 @@ static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg, } } -static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val) -{ - skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL); - skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG; -} - -static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb) -{ - return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL; -} - -static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb) -{ - return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL); -} - static inline void net_zcopy_put(struct ubuf_info *uarg) { if (uarg) @@ -1872,8 +1856,7 @@ static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success) struct ubuf_info *uarg = skb_zcopy(skb); if (uarg) { - if (!skb_zcopy_is_nouarg(skb)) - uarg->ops->complete(skb, uarg, zerocopy_success); + uarg->ops->complete(skb, uarg, zerocopy_success); skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY; } -- cgit v1.2.3 From 24b620729e53d978b3e425f55bc66efd3bab1f59 Mon Sep 17 00:00:00 2001 From: Puranjay Mohan Date: Mon, 10 Aug 2026 06:35:36 -0700 Subject: perf/core: Fill branch entries with a single assignment perf_clear_branch_entry_bitfields() clears the bitfields of struct perf_branch_entry one by one and leaves from/to alone, since callers overwrite those straight away. The list has to be kept in sync with the struct by hand and has already fallen behind: new_type and priv were added to perf_branch_entry and never added here. Only BRBE writes those two, and neither for every record. brbe_set_perf_entry_type() leaves new_type alone for a branch type it does not recognise, and priv is not set for source-only records. arm_pmuv3.c allocates the per-CPU branch stack with kmalloc(), so such a record reaches userspace with whatever the slot held: uninitialised kmalloc() data on the first pass over the buffer, the previous record's values after that. Nothing under arch/x86/events/ writes either field, so only arm64 is affected. Assign the whole entry at each site instead. Everything not named is then zero, and there is no list to keep in sync. The bitfields add up to exactly 64 bits, so the struct has no padding to leave undefined. perf_clear_branch_entry_bitfields() has no callers left, so remove it. perf_entry_from_brbe_regset() assigns an empty literal instead, since it fills from/to conditionally. PERF_BR_SPEC_NA is 0, so dropping the explicit spec assignment changes nothing. Fixes: b190bc4ac9e6 ("perf: Extend branch type classification") Fixes: 5402d25aa571 ("perf: Capture branch privilege information") Suggested-by: Peter Zijlstra Signed-off-by: Puranjay Mohan Signed-off-by: Peter Zijlstra (Intel) Tested-by: Yifan Wu Link: https://patch.msgid.link/20260810133540.1947118-4-puranjay@kernel.org --- include/linux/perf_event.h | 17 ----------------- 1 file changed, 17 deletions(-) (limited to 'include/linux') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 5842552294c1..915c6fd3f084 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1467,23 +1467,6 @@ static inline u32 perf_sample_data_size(struct perf_sample_data *data, return size; } -/* - * Clear all bitfields in the perf_branch_entry. - * The to and from fields are not cleared because they are - * systematically modified by caller. - */ -static inline void perf_clear_branch_entry_bitfields(struct perf_branch_entry *br) -{ - br->mispred = 0; - br->predicted = 0; - br->in_tx = 0; - br->abort = 0; - br->cycles = 0; - br->type = 0; - br->spec = PERF_BR_SPEC_NA; - br->reserved = 0; -} - extern void perf_output_sample(struct perf_output_handle *handle, struct perf_event_header *header, struct perf_sample_data *data, -- cgit v1.2.3 From b78b728e21c32ec4c330b299f657fb1eb02dffc2 Mon Sep 17 00:00:00 2001 From: Hao Ge Date: Wed, 23 Sep 2026 14:37:59 +0800 Subject: netfs: Fix missing alloc tagging of direct mempool allocations Commit 1d78d56c43ef ("netfs: Fix folio_queue ENOMEM in writeback by adding a mempool") added a mempool for the folio_queues and made the request, subrequest and folio_queue allocations distinguish between writeback and everything else. Writeback is part of memory reclaim and must not fail due to ENOMEM, so it allocates under GFP_NOFS through mempool_alloc(), which may dip into the pool's reserve and, if that runs empty, wait for elements to be returned. The GFP_KERNEL paths, which can return -ENOMEM to their callers, invoke the pool's ->alloc() callback directly instead. The direct call, however, skips the alloc_hooks() wrapper that the mempool_alloc() macro provides. The pool callbacks, mempool_alloc_slab() and mempool_kmalloc(), call kmem_cache_alloc_noprof() and kmalloc_noprof() and rely on current->alloc_tag having been set by the caller. With CONFIG_MEM_ALLOC_PROFILING_DEBUG=y this leads to current->alloc_tag not set WARNING: ./include/linux/alloc_tag.h:161 at __alloc_tagging_slab_alloc_hook alloc_tag was not set WARNING: ./include/linux/alloc_tag.h:166 at __alloc_tagging_slab_free_hook at allocation and free time respectively, as reported when reading files on a CIFS mount. The allocations are also missing from /proc/allocinfo. Wrap the direct ->alloc() invocations in alloc_hooks() with a new mempool_alloc_noreserve() helper in include/linux/mempool.h, next to the other alloc_hooks()-wrapped macros such as mempool_alloc(). The GFP_KERNEL paths keep their failable allocation semantics, they just get tagged now. Fixes: 1d78d56c43ef ("netfs: Fix folio_queue ENOMEM in writeback by adding a mempool") Reported-by: Erhard Furtner Closes: https://lore.kernel.org/all/0b004319-9ef7-437c-a4dd-174d6a9a83db@mailbox.org/ Tested-by: Erhard Furtner Suggested-by: Suren Baghdasaryan Cc: stable@vger.kernel.org Signed-off-by: Hao Ge Link: https://patch.msgid.link/20260923063759.34667-1-hao.ge@linux.dev Acked-by: Vlastimil Babka (SUSE) Signed-off-by: Christian Brauner (Amutable) --- include/linux/mempool.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mempool.h b/include/linux/mempool.h index a0fa6d43e0dc..6da502aef2f7 100644 --- a/include/linux/mempool.h +++ b/include/linux/mempool.h @@ -70,6 +70,13 @@ int mempool_alloc_bulk_noprof(struct mempool *pool, void **elem, #define mempool_alloc_bulk(...) \ alloc_hooks(mempool_alloc_bulk_noprof(__VA_ARGS__)) +/* + * Allocate a new element without dipping into the pool's reserves or + * waiting. Returns NULL on failure. + */ +#define mempool_alloc_noreserve(_pool, _gfp) \ + alloc_hooks((_pool)->alloc(_gfp, (_pool)->pool_data)) + void *mempool_alloc_preallocated(struct mempool *pool) __malloc; void mempool_free(void *element, struct mempool *pool); unsigned int mempool_free_bulk(struct mempool *pool, void **elem, -- cgit v1.2.3