syzbot

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BUG: KCSAN: data-race in get_signal / io_req_task_work_add

write to 0xffff888136bea0ec of 4 bytes by task 4521 on cpu 0:
 get_signal+0xe96/0x15d0 kernel/signal.c:2753
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x104/0x170 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x40/0x50 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888136bea0ec of 4 bytes by task 4524 on cpu 1:
 io_req_task_work_add+0x2c/0x320 fs/io_uring.c:1909
 io_req_task_queue fs/io_uring.c:2019 [inline]
 __io_queue_deferred fs/io_uring.c:1275 [inline]
 io_commit_cqring+0x5dc/0x630 fs/io_uring.c:1324
 io_req_complete_post+0x2df/0x570 fs/io_uring.c:1555
 __io_req_complete fs/io_uring.c:1579 [inline]
 __io_complete_rw+0x3a0/0x430 fs/io_uring.c:2522
 io_complete_rw+0x1b/0x20 fs/io_uring.c:2529
 io_rw_done fs/io_uring.c:2756 [inline]
 kiocb_done+0x1d3/0x8d0 fs/io_uring.c:2780
 io_read fs/io_uring.c:3359 [inline]
 io_issue_sqe+0x410a/0x6080 fs/io_uring.c:6056
 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: 1 PID: 4524 Comm: iou-wrk-4521 Not tainted 5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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