[moderation] [fs?] KCSAN: data-race in pipe_poll / pipe_release (12)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d0e88704d96c Merge tag 'clk-fixes-for-linus' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1168797c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=655255e3ef31c19b
dashboard link: https://syzkaller.appspot.com/bug?extid=7949d8bc2ada64fe2e40
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
CC: [bra...@kernel.org ja...@suse.cz linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c545adaede90/disk-d0e88704.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/149e9404ad7b/vmlinux-d0e88704.xz
kernel image: https://storage.googleapis.com/syzbot-assets/669bfb359225/bzImage-d0e88704.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7949d8...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in pipe_poll / pipe_release

read-write to 0xffff8881609948a4 of 4 bytes by task 10024 on cpu 1:
pipe_release+0x6e/0x1d0 fs/pipe.c:731
__fput+0x29b/0x650 fs/file_table.c:468
____fput+0x1c/0x30 fs/file_table.c:496
task_work_run+0x131/0x1a0 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xed/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881609948a4 of 4 bytes by task 18582 on cpu 0:
pipe_poll+0x215/0x250 fs/pipe.c:702
vfs_poll include/linux/poll.h:82 [inline]
aio_poll_complete_work+0xd4/0x350 fs/aio.c:1733
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
worker_thread+0x582/0x770 kernel/workqueue.c:3427
kthread+0x489/0x510 kernel/kthread.c:463
ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 18582 Comm: kworker/0:1 Tainted: G W syzkaller #0 PREEMPT(voluntary)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events aio_poll_complete_work
==================================================================


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