syzbot

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BUG: KCSAN: data-race in __io_cqring_fill_event / io_req_defer

write to 0xffff8881317d3c80 of 4 bytes by task 5363 on cpu 0:
 io_get_cqring fs/io_uring.c:1384 [inline]
 __io_cqring_fill_event+0xfd/0x350 fs/io_uring.c:1566
 io_req_complete_post+0x58/0x540 fs/io_uring.c:1590
 __io_req_complete fs/io_uring.c:1645 [inline]
 __io_complete_rw+0x3b5/0x470 fs/io_uring.c:2495
 io_complete_rw+0x1b/0x20 fs/io_uring.c:2502
 io_rw_done fs/io_uring.c:2736 [inline]
 kiocb_done+0x1b0/0x420 fs/io_uring.c:2760
 io_read fs/io_uring.c:3341 [inline]
 io_issue_sqe+0x36c5/0x6750 fs/io_uring.c:6120
 io_wq_submit_work+0x113/0x270 fs/io_uring.c:6257
 io_worker_handle_work+0x8cb/0xaf0 fs/io-wq.c:496
 io_wqe_worker+0x185/0x520 fs/io-wq.c:545
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff8881317d3c80 of 4 bytes by task 5358 on cpu 1:
 req_need_defer fs/io_uring.c:1213 [inline]
 io_req_defer+0x358/0x4a0 fs/io_uring.c:6007
 io_queue_sqe fs/io_uring.c:6456 [inline]
 io_submit_sqe+0x154d/0x3360 fs/io_uring.c:6631
 io_submit_sqes+0x5bd/0xbd0 fs/io_uring.c:6739
 __do_sys_io_uring_enter fs/io_uring.c:9336 [inline]
 __se_sys_io_uring_enter+0x1e1/0xa80 fs/io_uring.c:9278
 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:9278
 do_syscall_64+0x44/0x80 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5358 Comm: syz-executor.4 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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