KCSAN: data-race in tcp_disconnect / tcp_poll

[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=12fd83f6500000
kernel config: https://syzkaller.appspot.com/x/.config?x=e0bbcd06922dbd46
dashboard link: https://syzkaller.appspot.com/bug?extid=2326116798df66b56cd5
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [and...@kernel.org a...@kernel.org b...@vger.kernel.org dan...@iogearbox.net da...@davemloft.net edum...@google.com john.fa...@gmail.com ka...@fb.com kps...@chromium.org ku...@kernel.org kuz...@ms2.inr.ac.ru linux-...@vger.kernel.org net...@vger.kernel.org songliu...@fb.com y...@fb.com yosh...@linux-ipv6.org]

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+232611...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in tcp_disconnect / tcp_poll

write to 0xffff88802acc94f0 of 4 bytes by task 528 on cpu 0:
tcp_disconnect+0x15a/0xd40 net/ipv4/tcp.c:2653
__inet_stream_connect+0x16e/0x690 net/ipv4/af_inet.c:630
inet_stream_connect+0x44/0x70 net/ipv4/af_inet.c:725
__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 0xffff88802acc94f0 of 4 bytes by task 514 on cpu 1:
tcp_poll+0x61f/0x690 net/ipv4/tcp.c:598
sock_poll+0x188/0x1a0 net/socket.c:1265
vfs_poll include/linux/poll.h:90 [inline]
do_pollfd fs/select.c:869 [inline]
do_poll fs/select.c:917 [inline]
do_sys_poll+0x611/0xb80 fs/select.c:1011
__do_sys_ppoll fs/select.c:1111 [inline]
__se_sys_ppoll+0x169/0x1b0 fs/select.c:1091
__x64_sys_ppoll+0x63/0x70 fs/select.c:1091
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: 1 PID: 514 Comm: syz-executor.2 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.