KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c2e7554e Merge tag 'gfs2-v5.10-rc4-fixes' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17d99fdc500000
kernel config: https://syzkaller.appspot.com/x/.config?x=e9a6e9171a00e85a
dashboard link: https://syzkaller.appspot.com/bug?extid=a27265bf496b8672a66a
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [da...@davemloft.net ktk...@virtuozzo.com ku...@kernel.org linux-...@vger.kernel.org net...@vger.kernel.org pab...@redhat.com]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a27265...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in unix_dgram_connect / unix_dgram_poll

write to 0xffff8881066cde30 of 4 bytes by task 10041 on cpu 1:
unix_dgram_disconnected net/unix/af_unix.c:486 [inline]
unix_dgram_connect+0x792/0x860 net/unix/af_unix.c:1190
__sys_connect_file net/socket.c:1852 [inline]
__sys_connect+0x245/0x280 net/socket.c:1869
__do_sys_connect net/socket.c:1879 [inline]
__se_sys_connect net/socket.c:1876 [inline]
__x64_sys_connect+0x3d/0x50 net/socket.c:1876
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881066cde30 of 4 bytes by task 10031 on cpu 0:
unix_dgram_poll+0x6e/0x3b0 net/unix/af_unix.c:2692
sock_poll+0x188/0x1a0 net/socket.c:1265
vfs_poll include/linux/poll.h:90 [inline]
ep_item_poll fs/eventpoll.c:885 [inline]
ep_send_events_proc+0x227/0x5f0 fs/eventpoll.c:1742
ep_scan_ready_list+0x13e/0x330 fs/eventpoll.c:712
ep_send_events fs/eventpoll.c:1786 [inline]
ep_poll fs/eventpoll.c:1942 [inline]
do_epoll_wait+0x4b2/0x810 fs/eventpoll.c:2323
__do_sys_epoll_wait fs/eventpoll.c:2333 [inline]
__se_sys_epoll_wait fs/eventpoll.c:2330 [inline]
__x64_sys_epoll_wait+0x4d/0x60 fs/eventpoll.c:2330
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10031 Comm: syz-executor.3 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

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