[moderation] [fs?] KCSAN: data-race in pipe_lock / pipe_release (16)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 01a412d06bc5 Merge tag 'pull-ufs-fix' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17011b82580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c0dd0a92e88efc24
dashboard link: https://syzkaller.appspot.com/bug?extid=c8a8a00a347cf8270583
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
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/ede6f30c84ca/disk-01a412d0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/401f0382eacf/vmlinux-01a412d0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2a88235488d4/bzImage-01a412d0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c8a8a0...@syzkaller.appspotmail.com

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

read-write to 0xffff88812e0fa72c of 4 bytes by task 2081 on cpu 0:
put_pipe_info fs/pipe.c:712 [inline]
pipe_release+0x16a/0x1d0 fs/pipe.c:742
__fput+0x29b/0x650 fs/file_table.c:465
____fput+0x1c/0x30 fs/file_table.c:493
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+0xe4/0x100 kernel/entry/common.c:114
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88812e0fa72c of 4 bytes by task 2082 on cpu 1:
pipe_lock+0x17/0x50 fs/pipe.c:90
vmsplice_to_user fs/splice.c:1517 [inline]
__do_sys_vmsplice fs/splice.c:1609 [inline]
__se_sys_vmsplice+0x230/0x10f0 fs/splice.c:1577
__x64_sys_vmsplice+0x55/0x70 fs/splice.c:1577
x64_sys_call+0x2f45/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:279
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000002 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2082 Comm: syz.5.10493 Not tainted 6.16.0-rc7-syzkaller-00018-g01a412d06bc5 #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================


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