KCSAN: data-race in io_cqring_overflow_flush / io_submit_sqe

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 32f741b0 Merge tag 'powerpc-5.10-5' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1427ed3d500000
kernel config: https://syzkaller.appspot.com/x/.config?x=c949fed53798f819
dashboard link: https://syzkaller.appspot.com/bug?extid=4140a16087dd1c9e5e8a
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [ax...@kernel.dk io-u...@vger.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.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4140a1...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in io_cqring_overflow_flush / io_submit_sqe

read-write to 0xffff8881071fdc44 of 1 bytes by task 31579 on cpu 0:
io_cqring_overflow_flush+0x8e/0xab0 fs/io_uring.c:1646
io_uring_cancel_task_requests fs/io_uring.c:8669 [inline]
__io_uring_files_cancel+0x21a/0x12e0 fs/io_uring.c:8767
io_uring_files_cancel include/linux/io_uring.h:51 [inline]
exit_files+0x6a/0xc0 fs/file.c:456
do_exit+0x428/0x1630 kernel/exit.c:804
do_group_exit+0xc8/0x170 kernel/exit.c:906
get_signal+0xf9b/0x1510 kernel/signal.c:2758
arch_do_signal+0x25/0x260 arch/x86/kernel/signal.c:811
exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
exit_to_user_mode_prepare+0xde/0x170 kernel/entry/common.c:191
syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881071fdc44 of 1 bytes by task 31585 on cpu 1:
io_submit_sqe+0x85/0x8f0 fs/io_uring.c:6354
io_submit_sqes+0x9a8/0x1720 fs/io_uring.c:6596
__do_sys_io_uring_enter fs/io_uring.c:8983 [inline]
__se_sys_io_uring_enter+0x52c/0xac0 fs/io_uring.c:8932
__x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:8932
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: 31585 Comm: syz-executor.2 Not tainted 5.10.0-rc6-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.