[moderation] [fs?] KCSAN: data-race in pipe_release / pipe_wait_writable (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: bfe62a454542 Merge tag 'soc-fixes-7.0-2' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=113598d2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=3a78dd265deac3a9
dashboard link: https://syzkaller.appspot.com/bug?extid=c81efef83e6c9bd13559
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
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/fc39db873abf/disk-bfe62a45.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2ab283b708df/vmlinux-bfe62a45.xz
kernel image: https://storage.googleapis.com/syzbot-assets/69cef2875afd/bzImage-bfe62a45.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c81efe...@syzkaller.appspotmail.com

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

read-write to 0xffff88811bdfb5ac of 4 bytes by task 9866 on cpu 1:
put_pipe_info fs/pipe.c:714 [inline]
pipe_release+0x16a/0x1d0 fs/pipe.c:744
__fput+0x29b/0x650 fs/file_table.c:469
fput_close_sync+0xad/0x190 fs/file_table.c:574
__do_sys_close fs/open.c:1509 [inline]
__se_sys_close fs/open.c:1494 [inline]
__x64_sys_close+0x55/0xf0 fs/open.c:1494
x64_sys_call+0x275d/0x3020 arch/x86/include/generated/asm/syscalls_64.h:4
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811bdfb5ac of 4 bytes by task 9863 on cpu 0:
pipe_lock fs/pipe.c:90 [inline]
pipe_wait_writable+0x202/0x250 fs/pipe.c:1084
wait_for_space fs/splice.c:1272 [inline]
vmsplice_to_pipe fs/splice.c:1551 [inline]
__do_sys_vmsplice fs/splice.c:1608 [inline]
__se_sys_vmsplice+0x42b/0xfd0 fs/splice.c:1578
__x64_sys_vmsplice+0x55/0x70 fs/splice.c:1578
x64_sys_call+0x28e9/0x3020 arch/x86/include/generated/asm/syscalls_64.h:279
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x12c/0x370 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: 0 UID: 0 PID: 9863 Comm: syz.1.2745 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup