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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 83a7eefedc9b Linux 6.10-rc3
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16f50102980000
kernel config: https://syzkaller.appspot.com/x/.config?x=68336ea4b6f4fc09
dashboard link: https://syzkaller.appspot.com/bug?extid=dfb0715dc383d6b65992
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/dc4448d7f810/disk-83a7eefe.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d1b7e727f29b/vmlinux-83a7eefe.xz
kernel image: https://storage.googleapis.com/syzbot-assets/470dd9374113/bzImage-83a7eefe.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dfb071...@syzkaller.appspotmail.com

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

read-write to 0xffff88811864e66c of 4 bytes by task 3581 on cpu 0:
put_pipe_info fs/pipe.c:712 [inline]
pipe_release+0x164/0x1c0 fs/pipe.c:742
__fput+0x2c2/0x660 fs/file_table.c:422
____fput+0x15/0x20 fs/file_table.c:450
task_work_run+0x13a/0x1a0 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811864e66c of 4 bytes by task 3586 on cpu 1:
pipe_lock fs/pipe.c:91 [inline]
pipe_double_lock+0x2e/0xa0 fs/pipe.c:111
splice_pipe_to_pipe fs/splice.c:1765 [inline]
do_splice+0x32e/0x1120 fs/splice.c:1331
__do_splice fs/splice.c:1436 [inline]
__do_sys_splice fs/splice.c:1652 [inline]
__se_sys_splice+0x24c/0x390 fs/splice.c:1634
__x64_sys_splice+0x78/0x90 fs/splice.c:1634
x64_sys_call+0x297f/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:276
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

value changed: 0x00000002 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3586 Comm: syz-executor.2 Not tainted 6.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================


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