[moderation] [fs?] KCSAN: data-race in pipe_poll / pipe_resize_ring (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 99fa936e8e4f Merge tag 'affs-6.14-rc5-tag' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14f1b5a8580000
kernel config: https://syzkaller.appspot.com/x/.config?x=523b0e2f15224775
dashboard link: https://syzkaller.appspot.com/bug?extid=f8294130e385e115a5f9
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
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/a28c1cb92a01/disk-99fa936e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/229349d043c8/vmlinux-99fa936e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/49768322c46d/bzImage-99fa936e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f82941...@syzkaller.appspotmail.com

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

write to 0xffff8881151ef7d8 of 4 bytes by task 3940 on cpu 1:
pipe_resize_ring+0x29d/0x330 fs/pipe.c:1327
pipe_set_size fs/pipe.c:1378 [inline]
pipe_fcntl+0x2f7/0x360 fs/pipe.c:1417
do_fcntl+0x5a2/0xe10 fs/fcntl.c:543
__do_sys_fcntl fs/fcntl.c:591 [inline]
__se_sys_fcntl+0xbd/0x1b0 fs/fcntl.c:576
__x64_sys_fcntl+0x43/0x50 fs/fcntl.c:576
x64_sys_call+0x2129/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:73
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881151ef7d8 of 4 bytes by task 3943 on cpu 0:
pipe_poll+0x1ee/0x250 fs/pipe.c:695
vfs_poll include/linux/poll.h:82 [inline]
__io_arm_poll_handler+0x1e5/0xd50 io_uring/poll.c:582
io_poll_add+0x6b/0xf0 io_uring/poll.c:892
io_issue_sqe+0x15f/0xb70 io_uring/io_uring.c:1737
io_queue_sqe io_uring/io_uring.c:1947 [inline]
io_submit_sqe io_uring/io_uring.c:2204 [inline]
io_submit_sqes+0x680/0x1070 io_uring/io_uring.c:2321
__io_sq_thread io_uring/sqpoll.c:189 [inline]
io_sq_thread+0x791/0x1100 io_uring/sqpoll.c:312
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x00000010 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3943 Comm: iou-sqp-3940 Not tainted 6.14.0-rc5-syzkaller-00013-g99fa936e8e4f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.