syzbot

==================================================================
BUG: KCSAN: data-race in __io_cqring_overflow_flush / futex_wait_queue_me

write to 0xffff8880251a402c of 4 bytes by task 27530 on cpu 0:
 freezer_count include/linux/freezer.h:121 [inline]
 freezable_schedule include/linux/freezer.h:173 [inline]
 futex_wait_queue_me+0x1a8/0x250 kernel/futex.c:2606
 futex_wait+0x145/0x3d0 kernel/futex.c:2708
 do_futex+0x105d/0x1cc0 kernel/futex.c:3736
 __do_sys_futex kernel/futex.c:3799 [inline]
 __se_sys_futex+0x2a8/0x390 kernel/futex.c:3765
 __x64_sys_futex+0x74/0x80 kernel/futex.c:3765
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880251a402c of 4 bytes by task 27511 on cpu 1:
 io_match_task fs/io_uring.c:1075 [inline]
 __io_cqring_overflow_flush+0x184/0x770 fs/io_uring.c:1785
 io_cqring_overflow_flush fs/io_uring.c:1835 [inline]
 io_uring_cancel_task_requests+0x71b/0xba0 fs/io_uring.c:8977
 __io_uring_files_cancel+0x9b/0x200 fs/io_uring.c:9067
 io_uring_files_cancel include/linux/io_uring.h:51 [inline]
 do_exit+0x19a/0x1690 kernel/exit.c:780
 do_group_exit+0xce/0x180 kernel/exit.c:922
 get_signal+0xdce/0x14e0 kernel/signal.c:2773
 arch_do_signal_or_restart+0x2a/0x270 arch/x86/kernel/signal.c:811
 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+0x11a/0x1b0 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 27511 Comm: syz-executor.3 Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================