KCSAN: data-race in sock_alloc_send_pskb / unix_dgram_connect

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 111e91a6 Merge tag 's390-5.10-4' of git://git.kernel.org/p..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=145e239a500000
kernel config: https://syzkaller.appspot.com/x/.config?x=e0bbcd06922dbd46
dashboard link: https://syzkaller.appspot.com/bug?extid=05a6bf13abb9fa29b886
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+05a6bf...@syzkaller.appspotmail.com

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

write to 0xffff888107848e30 of 4 bytes by task 19878 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 0xffff888107848e30 of 4 bytes by task 19888 on cpu 0:
sock_error include/net/sock.h:2217 [inline]
sock_alloc_send_pskb+0xe0/0x470 net/core/sock.c:2309
unix_dgram_sendmsg+0x485/0x15f0 net/unix/af_unix.c:1670
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg net/socket.c:671 [inline]
____sys_sendmsg+0x352/0x4c0 net/socket.c:2353
___sys_sendmsg net/socket.c:2407 [inline]
__sys_sendmmsg+0x335/0x4b0 net/socket.c:2497
__do_sys_sendmmsg net/socket.c:2526 [inline]
__se_sys_sendmmsg net/socket.c:2523 [inline]
__x64_sys_sendmmsg+0x53/0x60 net/socket.c:2523
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: 19888 Comm: syz-executor.1 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.