syzbot

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BUG: KCSAN: data-race in __io_cqring_fill_event / io_wake_function

write to 0xffff888139774c40 of 4 bytes by task 4421 on cpu 1:
 io_get_cqring fs/io_uring.c:1352 [inline]
 __io_cqring_fill_event+0x135/0x400 fs/io_uring.c:1491
 io_req_complete_post+0x49/0x570 fs/io_uring.c:1531
 io_issue_sqe+0x3c40/0x6080 fs/io_uring.c:4428
 io_wq_submit_work+0x112/0x300 fs/io_uring.c:6193
 io_worker_handle_work+0xbbb/0xe20 fs/io-wq.c:451
 io_wqe_worker+0x1e5/0x580 fs/io-wq.c:501
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff888139774c40 of 4 bytes by task 4544 on cpu 0:
 __io_cqring_events fs/io_uring.c:1336 [inline]
 io_cqring_events fs/io_uring.c:2178 [inline]
 io_should_wake fs/io_uring.c:6864 [inline]
 io_wake_function+0x40/0x130 fs/io_uring.c:6878
 __wake_up_common+0xbc/0x130 kernel/sched/wait.c:108
 __wake_up_common_lock kernel/sched/wait.c:138 [inline]
 __wake_up+0x80/0xc0 kernel/sched/wait.c:157
 io_cqring_ev_posted+0x4c/0x220 fs/io_uring.c:1373
 io_req_complete_post+0x2f7/0x570 fs/io_uring.c:1559
 io_issue_sqe+0x3c40/0x6080 fs/io_uring.c:4428
 io_wq_submit_work+0x112/0x300 fs/io_uring.c:6193
 io_worker_handle_work+0xbbb/0xe20 fs/io-wq.c:451
 io_wqe_worker+0x1e5/0x580 fs/io-wq.c:501
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4544 Comm: iou-wrk-4387 Tainted: G        W         5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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