kernel/linux.git/include/trace, branch v6.12.80

rxrpc: Fix recvmsg() unconditional requeue

2026-03-25T10:08:44+00:00

[ Upstream commit 2c28769a51deb6022d7fbd499987e237a01dd63a ] If rxrpc_recvmsg() fails because MSG_DONTWAIT was specified but the call at the front of the recvmsg queue already has its mutex locked, it requeues the call - whether or not the call is already queued. The call may be on the queue because MSG_PEEK was also passed and so the call was not dequeued or because the I/O thread requeued it. The unconditional requeue may then corrupt the recvmsg queue, leading to things like UAFs or refcount underruns. Fix this by only requeuing the call if it isn't already on the queue - and moving it to the front if it is already queued. If we don't queue it, we have to put the ref we obtained by dequeuing it. Also, MSG_PEEK doesn't dequeue the call so shouldn't call rxrpc_notify_socket() for the call if we didn't use up all the data on the queue, so fix that also. Fixes: 540b1c48c37a ("rxrpc: Fix deadlock between call creation and sendmsg/recvmsg") Reported-by: Faith Reported-by: Pumpkin Chang Signed-off-by: David Howells Acked-by: Marc Dionne cc: Nir Ohfeld cc: Willy Tarreau cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/95163.1768428203@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski [Use spin_unlock instead of spin_unlock_irq to maintain context consistency.] Signed-off-by: Robert Garcia Signed-off-by: Greg Kroah-Hartman

mm/tracing: rss_stat: ensure curr is false from kthread context

2026-03-25T10:08:32+00:00

commit 079c24d5690262e83ee476e2a548e416f3237511 upstream. The rss_stat trace event allows userspace tools, like Perfetto [1], to inspect per-process RSS metric changes over time. The curr field was introduced to rss_stat in commit e4dcad204d3a ("rss_stat: add support to detect RSS updates of external mm"). Its intent is to indicate whether the RSS update is for the mm_struct of the current execution context; and is set to false when operating on a remote mm_struct (e.g., via kswapd or a direct reclaimer). However, an issue arises when a kernel thread temporarily adopts a user process's mm_struct. Kernel threads do not have their own mm_struct and normally have current->mm set to NULL. To operate on user memory, they can "borrow" a memory context using kthread_use_mm(), which sets current->mm to the user process's mm. This can be observed, for example, in the USB Function Filesystem (FFS) driver. The ffs_user_copy_worker() handles AIO completions and uses kthread_use_mm() to copy data to a user-space buffer. If a page fault occurs during this copy, the fault handler executes in the kthread's context. At this point, current is the kthread, but current->mm points to the user process's mm. Since the rss_stat event (from the page fault) is for that same mm, the condition current->mm == mm becomes true, causing curr to be incorrectly set to true when the trace event is emitted. This is misleading because it suggests the mm belongs to the kthread, confusing userspace tools that track per-process RSS changes and corrupting their mm_id-to-process association. Fix this by ensuring curr is always false when the trace event is emitted from a kthread context by checking for the PF_KTHREAD flag. Link: https://lkml.kernel.org/r/20260219233708.1971199-1-kaleshsingh@google.com Link: https://perfetto.dev/ [1] Fixes: e4dcad204d3a ("rss_stat: add support to detect RSS updates of external mm") Signed-off-by: Kalesh Singh Acked-by: Zi Yan Acked-by: SeongJae Park Reviewed-by: Pedro Falcato Cc: "David Hildenbrand (Arm)" Cc: Joel Fernandes Cc: Lorenzo Stoakes Cc: Minchan Kim Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: [5.10+] Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

tracing/dma: Cap dma_map_sg tracepoint arrays to prevent buffer overflow

2026-02-19T15:29:54+00:00

[ Upstream commit daafcc0ef0b358d9d622b6e3b7c43767aa3814ee ] The dma_map_sg tracepoint can trigger a perf buffer overflow when tracing large scatter-gather lists. With devices like virtio-gpu creating large DRM buffers, nents can exceed 1000 entries, resulting in: phys_addrs: 1000 * 8 bytes = 8,000 bytes dma_addrs: 1000 * 8 bytes = 8,000 bytes lengths: 1000 * 4 bytes = 4,000 bytes Total: ~20,000 bytes This exceeds PERF_MAX_TRACE_SIZE (8192 bytes), causing: WARNING: CPU: 0 PID: 5497 at kernel/trace/trace_event_perf.c:405 perf buffer not large enough, wanted 24620, have 8192 Cap all three dynamic arrays at 128 entries using min() in the array size calculation. This ensures arrays are only as large as needed (up to the cap), avoiding unnecessary memory allocation for small operations while preventing overflow for large ones. The tracepoint now records the full nents/ents counts and a truncated flag so users can see when data has been capped. Changes in v2: - Use min(nents, DMA_TRACE_MAX_ENTRIES) for dynamic array sizing instead of fixed DMA_TRACE_MAX_ENTRIES allocation (feedback from Steven Rostedt) - This allocates only what's needed up to the cap, avoiding waste for small operations Reported-by: syzbot+28cea38c382fd15e751a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=28cea38c382fd15e751a Tested-by: syzbot+28cea38c382fd15e751a@syzkaller.appspotmail.com Signed-off-by: Deepanshu Kartikey Reviwed-by: Sean Anderson Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20260130155215.69737-1-kartikey406@gmail.com Signed-off-by: Sasha Levin

btrfs: fix NULL dereference on root when tracing inode eviction

2026-01-17T15:31:20+00:00

[ Upstream commit f157dd661339fc6f5f2b574fe2429c43bd309534 ] When evicting an inode the first thing we do is to setup tracing for it, which implies fetching the root's id. But in btrfs_evict_inode() the root might be NULL, as implied in the next check that we do in btrfs_evict_inode(). Hence, we either should set the ->root_objectid to 0 in case the root is NULL, or we move tracing setup after checking that the root is not NULL. Setting the rootid to 0 at least gives us the possibility to trace this call even in the case when the root is NULL, so that's the solution taken here. Fixes: 1abe9b8a138c ("Btrfs: add initial tracepoint support for btrfs") Reported-by: syzbot+d991fea1b4b23b1f6bf8@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d991fea1b4b23b1f6bf8 Signed-off-by: Miquel Sabaté Solà Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

btrfs: tracepoints: use btrfs_root_id() to get the id of a root

2026-01-17T15:31:20+00:00

[ Upstream commit 0f987c099d22c3b8c7d94fd13f957792e46f79c9 ] Instead of open coding btrfs_root_id() to get the ID of a root, use the helper in the trace points, which also makes the code less verbose. Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Stable-dep-of: f157dd661339 ("btrfs: fix NULL dereference on root when tracing inode eviction") Signed-off-by: Sasha Levin

NFSD: Remove NFSERR_EAGAIN

2026-01-17T15:31:15+00:00

commit c6c209ceb87f64a6ceebe61761951dcbbf4a0baa upstream. I haven't found an NFSERR_EAGAIN in RFCs 1094, 1813, 7530, or 8881. None of these RFCs have an NFS status code that match the numeric value "11". Based on the meaning of the EAGAIN errno, I presume the use of this status in NFSD means NFS4ERR_DELAY. So replace the one usage of nfserr_eagain, and remove it from NFSD's NFS status conversion tables. As far as I can tell, NFSERR_EAGAIN has existed since the pre-git era, but was not actually used by any code until commit f4e44b393389 ("NFSD: delay unmount source's export after inter-server copy completed."), at which time it become possible for NFSD to return a status code of 11 (which is not valid NFS protocol). Fixes: f4e44b393389 ("NFSD: delay unmount source's export after inter-server copy completed.") Cc: stable@vger.kernel.org Reviewed-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

dma-mapping: fix direction in dma_alloc direction traces

2025-10-19T14:33:34+00:00

commit 16abbabc004bedeeaa702e11913da9d4fa70e63a upstream. Set __entry->dir to the actual "dir" parameter of all trace events in dma_alloc_class. This struct member was left uninitialized by mistake. Signed-off-by: Petr Tesarik Fixes: 3afff779a725 ("dma-mapping: trace dma_alloc/free direction") Cc: stable@vger.kernel.org Reviewed-by: Sean Anderson Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20251001061028.412258-1-ptesarik@suse.com Signed-off-by: Greg Kroah-Hartman

filelock: add FL_RECLAIM to show_fl_flags() macro

2025-10-15T09:59:53+00:00

[ Upstream commit c593b9d6c446510684da400833f9d632651942f0 ] Show the FL_RECLAIM flag symbolically in tracepoints. Fixes: bb0a55bb7148 ("nfs: don't allow reexport reclaims") Signed-off-by: Jeff Layton Link: https://lore.kernel.org/20250903-filelock-v1-1-f2926902962d@kernel.org Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

dma-mapping: trace more error paths

2025-09-19T14:35:42+00:00

[ Upstream commit 68b6dbf1f441c4eba3b8511728a41cf9b01dca35 ] It can be surprising to the user if DMA functions are only traced on success. On failure, it can be unclear what the source of the problem is. Fix this by tracing all functions even when they fail. Cases where we BUG/WARN are skipped, since those should be sufficiently noisy already. Signed-off-by: Sean Anderson Reviewed-by: Steven Rostedt (Google) Signed-off-by: Christoph Hellwig Stable-dep-of: 7e2368a21741 ("dma-debug: don't enforce dma mapping check on noncoherent allocations") Signed-off-by: Sasha Levin

dma-mapping: use trace_dma_alloc for dma_alloc* instead of using trace_dma_map

2025-09-19T14:35:42+00:00

[ Upstream commit c4484ab86ee00f2d9236e2851621ea02c105f4cc ] In some cases, we use trace_dma_map to trace dma_alloc* functions. This generally follows dma_debug. However, this does not record all of the relevant information for allocations, such as GFP flags. Create new dma_alloc tracepoints for these functions. Note that while dma_alloc_noncontiguous may allocate discontiguous pages (from the CPU's point of view), the device will only see one contiguous mapping. Therefore, we just need to trace dma_addr and size. Signed-off-by: Sean Anderson Reviewed-by: Steven Rostedt (Google) Signed-off-by: Christoph Hellwig Stable-dep-of: 7e2368a21741 ("dma-debug: don't enforce dma mapping check on noncoherent allocations") Signed-off-by: Sasha Levin