[moderation] [fs?] KCSAN: data-race in do_epoll_wait / ep_poll_callback (10)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d2da77f431ac Merge tag 'parisc-for-6.7-rc3' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15ed4662e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=8c1151391aefc0c3
dashboard link: https://syzkaller.appspot.com/bug?extid=aba068c680f0815ffd5f
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bra...@kernel.org 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/0ebc29947781/disk-d2da77f4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a82ec858fbee/vmlinux-d2da77f4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d45f2fa85085/bzImage-d2da77f4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+aba068...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in do_epoll_wait / ep_poll_callback

write to 0xffff88811ce953e8 of 4 bytes by task 10379 on cpu 1:
ep_send_events fs/eventpoll.c:1745 [inline]
ep_poll fs/eventpoll.c:1864 [inline]
do_epoll_wait+0x805/0xe70 fs/eventpoll.c:2318
do_epoll_pwait fs/eventpoll.c:2352 [inline]
__do_sys_epoll_pwait fs/eventpoll.c:2365 [inline]
__se_sys_epoll_pwait+0x15f/0x280 fs/eventpoll.c:2359
__x64_sys_epoll_pwait+0x78/0x90 fs/eventpoll.c:2359
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88811ce953e8 of 4 bytes by task 10377 on cpu 0:
ep_poll_callback+0x4b5/0x5a0 fs/eventpoll.c:1246
__wake_up_common kernel/sched/wait.c:89 [inline]
__wake_up_common_lock kernel/sched/wait.c:106 [inline]
__wake_up+0x64/0xa0 kernel/sched/wait.c:127
pipe_release+0x114/0x1c0 fs/pipe.c:739
__fput+0x299/0x630 fs/file_table.c:394
__fput_sync+0x44/0x50 fs/file_table.c:475
__do_sys_close fs/open.c:1590 [inline]
__se_sys_close+0xfa/0x1a0 fs/open.c:1575
__x64_sys_close+0x1f/0x30 fs/open.c:1575
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x40000018 -> 0x40000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10377 Comm: syz-executor.3 Not tainted 6.7.0-rc2-syzkaller-00265-gd2da77f431ac #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================


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[syzbot]

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