kernel/linux.git/include/trace, branch v6.19.11

netfs: Fix the handling of stream->front by removing it

2026-04-02T11:25:56+00:00

[ Upstream commit 0e764b9d46071668969410ec5429be0e2f38c6d3 ] The netfs_io_stream::front member is meant to point to the subrequest currently being collected on a stream, but it isn't actually used this way by direct write (which mostly ignores it). However, there's a tracepoint which looks at it. Further, stream->front is actually redundant with stream->subrequests.next. Fix the potential problem in the direct code by just removing the member and using stream->subrequests.next instead, thereby also simplifying the code. Fixes: a0b4c7a49137 ("netfs: Fix unbuffered/DIO writes to dispatch subrequests in strict sequence") Reported-by: Paulo Alcantara Signed-off-by: David Howells Link: https://patch.msgid.link/4158599.1774426817@warthog.procyon.org.uk Reviewed-by: Paulo Alcantara (Red Hat) cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

tracing: Revert "tracing: Remove pid in task_rename tracing output"

2026-04-02T11:25:15+00:00

[ Upstream commit a6f22e50c7d51aa225c392c62c33f0fae11f734d ] This reverts commit e3f6a42272e028c46695acc83fc7d7c42f2750ad. The commit says that the tracepoint only deals with the current task, however the following case is not current task: comm_write() { p = get_proc_task(inode); if (!p) return -ESRCH; if (same_thread_group(current, p)) set_task_comm(p, buffer); } where set_task_comm() calls __set_task_comm() which records the update of p and not current. So revert the patch to show pid. Cc: Cc: Cc: Cc: Link: https://patch.msgid.link/20260306075954.4533-1-xuewen.yan@unisoc.com Fixes: e3f6a42272e0 ("tracing: Remove pid in task_rename tracing output") Reported-by: Guohua Yan Signed-off-by: Xuewen Yan Reviewed-by: Steven Rostedt (Google) Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin

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

2026-03-19T15:15:06+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

netfs: Fix unbuffered/DIO writes to dispatch subrequests in strict sequence

2026-03-12T11:09:44+00:00

[ Upstream commit a0b4c7a49137ed21279f354eb59f49ddae8dffc2 ] Fix netfslib such that when it's making an unbuffered or DIO write, to make sure that it sends each subrequest strictly sequentially, waiting till the previous one is 'committed' before sending the next so that we don't have pieces landing out of order and potentially leaving a hole if an error occurs (ENOSPC for example). This is done by copying in just those bits of issuing, collecting and retrying subrequests that are necessary to do one subrequest at a time. Retrying, in particular, is simpler because if the current subrequest needs retrying, the source iterator can just be copied again and the subrequest prepped and issued again without needing to be concerned about whether it needs merging with the previous or next in the sequence. Note that the issuing loop waits for a subrequest to complete right after issuing it, but this wait could be moved elsewhere allowing preparatory steps to be performed whilst the subrequest is in progress. In particular, once content encryption is available in netfslib, that could be done whilst waiting, as could cleanup of buffers that have been completed. Fixes: 153a9961b551 ("netfs: Implement unbuffered/DIO write support") Signed-off-by: David Howells Link: https://patch.msgid.link/58526.1772112753@warthog.procyon.org.uk Tested-by: Steve French Reviewed-by: Paulo Alcantara (Red Hat) cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

Merge tag 'dma-mapping-6.19-2026-02-06' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

2026-02-06T18:27:42+00:00

Pull dma-mapping fixes from Marek Szyprowski: "Two minor fixes for the DMA-mapping subsystem: - check for the rare case of the allocation failure of the global CMA pool (Shanker Donthineni) - avoid perf buffer overflow when tracing large scatter-gather lists (Deepanshu Kartikey)" * tag 'dma-mapping-6.19-2026-02-06' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: dma: contiguous: Check return value of dma_contiguous_reserve_area() tracing/dma: Cap dma_map_sg tracepoint arrays to prevent buffer overflow

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

2026-02-02T07:41:17+00:00

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

rxrpc: Fix recvmsg() unconditional requeue

2026-01-19T18:07:06+00:00

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

Merge tag 'nfsd-6.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

2026-01-06T17:12:52+00:00

Pull nfsd fixes from Chuck Lever: "A set of NFSD fixes for stable that arrived after the merge window: - Remove an invalid NFS status code - Fix an fstests failure when using pNFS - Fix a UAF in v4_end_grace() - Fix the administrative interface used to revoke NFSv4 state - Fix a memory leak reported by syzbot" * tag 'nfsd-6.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: NFSD: net ref data still needs to be freed even if net hasn't startup nfsd: check that server is running in unlock_filesystem nfsd: use correct loop termination in nfsd4_revoke_states() nfsd: provide locking for v4_end_grace NFSD: Fix permission check for read access to executable-only files NFSD: Remove NFSERR_EAGAIN

Merge tag 'for-6.19-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2026-01-05T22:10:48+00:00

Pull btrfs fixes from David Sterba: - fix potential deadlock due to mismatching transaction states when waiting for the current transaction - fix squota accounting with nested snapshots - fix quota inheritance of qgroups with multiple parent qgroups - fix NULL inode pointer in evict tracepoint - fix writes beyond end of file on systems with 64K page size and 4K block size - fix logging of inodes after exchange rename - fix use after free when using ref_tracker feature - space reservation fixes * tag 'for-6.19-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix reservation leak in some error paths when inserting inline extent btrfs: do not free data reservation in fallback from inline due to -ENOSPC btrfs: fix use-after-free warning in btrfs_get_or_create_delayed_node() btrfs: always detect conflicting inodes when logging inode refs btrfs: fix beyond-EOF write handling btrfs: fix deadlock in wait_current_trans() due to ignored transaction type btrfs: fix NULL dereference on root when tracing inode eviction btrfs: qgroup: update all parent qgroups when doing quick inherit btrfs: fix qgroup_snapshot_quick_inherit() squota bug

NFSD: Remove NFSERR_EAGAIN

2026-01-02T18:43:41+00:00

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