KCSAN: data-race in create_io_worker / io_wqe_wake_worker (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d5beb314 Merge tag 'hyperv-fixes-signed' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=167d0e43500000
kernel config: https://syzkaller.appspot.com/x/.config?x=cf114765a0c30afa
dashboard link: https://syzkaller.appspot.com/bug?extid=90fe716183e9c4de4239
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+90fe71...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in create_io_worker / io_wqe_wake_worker

write to 0xffff888046dc4044 of 4 bytes by task 12794 on cpu 1:
create_io_worker+0x2cb/0x3a0 fs/io-wq.c:713
io_wq_manager+0x350/0x790 fs/io-wq.c:812
kthread+0x1fd/0x220 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff888046dc4044 of 4 bytes by task 12805 on cpu 0:
io_wqe_wake_worker+0x163/0x220 fs/io-wq.c:308
io_wqe_enqueue+0x2a5/0x320 fs/io-wq.c:919
io_wq_enqueue+0x3a/0x40 fs/io-wq.c:926
__io_queue_async_work fs/io_uring.c:1433 [inline]
__io_queue_deferred+0x206/0x570 fs/io_uring.c:1507
io_commit_cqring+0x457/0x460 fs/io_uring.c:1540
io_cqring_add_event fs/io_uring.c:1739 [inline]
__io_req_complete+0xe5/0x450 fs/io_uring.c:1782
io_issue_sqe+0x2f94/0x45e0 fs/io_uring.c:4260
io_wq_submit_work+0x27c/0x760 fs/io_uring.c:6064
io_worker_handle_work+0xd2a/0x1000 fs/io-wq.c:572
io_wqe_worker+0x202/0x810 fs/io-wq.c:614
kthread+0x1fd/0x220 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12805 Comm: io_wqe_worker-0 Not tainted 5.10.0-rc5-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.