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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f6cef5f8c37f Merge tag 'i3c/for-6.9' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1483daa5180000
kernel config: https://syzkaller.appspot.com/x/.config?x=8c3c081f20b130f6
dashboard link: https://syzkaller.appspot.com/bug?extid=842f25b7b118d03fc6a2
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/aedbebda3898/disk-f6cef5f8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6fb1ed41e8cc/vmlinux-f6cef5f8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/30502ff70726/bzImage-f6cef5f8.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+842f25...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in do_epoll_ctl / do_epoll_ctl

read-write to 0xffffffff883d72c0 of 8 bytes by task 15441 on cpu 1:
do_epoll_ctl+0x6f6/0x950 fs/eventpoll.c:2303
__do_sys_epoll_ctl fs/eventpoll.c:2386 [inline]
__se_sys_epoll_ctl fs/eventpoll.c:2377 [inline]
__x64_sys_epoll_ctl+0xc6/0xf0 fs/eventpoll.c:2377
do_syscall_64+0xd3/0x1d0
entry_SYSCALL_64_after_hwframe+0x6d/0x75

read to 0xffffffff883d72c0 of 8 bytes by task 15443 on cpu 0:
do_epoll_ctl+0x529/0x950 fs/eventpoll.c:2297
__do_sys_epoll_ctl fs/eventpoll.c:2386 [inline]
__se_sys_epoll_ctl fs/eventpoll.c:2377 [inline]
__x64_sys_epoll_ctl+0xc6/0xf0 fs/eventpoll.c:2377
do_syscall_64+0xd3/0x1d0
entry_SYSCALL_64_after_hwframe+0x6d/0x75

value changed: 0x000000000000000a -> 0x000000000000000c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15443 Comm: syz-executor.2 Tainted: G W 6.8.0-syzkaller-11409-gf6cef5f8c37f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
==================================================================


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[syzbot]

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