syzbot

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BUG: KCSAN: data-race in exit_mmap / io_ring_ctx_wait_and_kill

read-write to 0xffff88803e46b348 of 8 bytes by task 23445 on cpu 0:
 io_unaccount_mem fs/io_uring.c:7863 [inline]
 io_ring_ctx_wait_and_kill+0x2c3/0x370 fs/io_uring.c:8375
 io_uring_release+0x3e/0x50 fs/io_uring.c:8393
 __fput+0x243/0x4d0 fs/file_table.c:281
 ____fput+0x11/0x20 fs/file_table.c:314
 task_work_run+0x8e/0x110 kernel/task_work.c:151
 exit_task_work include/linux/task_work.h:30 [inline]
 do_exit+0x437/0x15a0 kernel/exit.c:809
 do_group_exit+0xc8/0x170 kernel/exit.c:906
 get_signal+0xf9b/0x1510 kernel/signal.c:2758
 arch_do_signal+0x25/0x260 arch/x86/kernel/signal.c:811
 exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
 exit_to_user_mode_prepare+0xde/0x170 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88803e46b348 of 8 bytes by task 23442 on cpu 1:
 exit_mmap+0x94/0x3b0 mm/mmap.c:3202
 __mmput+0xa2/0x220 kernel/fork.c:1079
 mmput+0x38/0x40 kernel/fork.c:1100
 exit_mm+0x307/0x370 kernel/exit.c:486
 do_exit+0x3c2/0x15a0 kernel/exit.c:796
 do_group_exit+0x16f/0x170 kernel/exit.c:906
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:917
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:915
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:915
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23442 Comm: syz-executor.1 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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