syzbot

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BUG: KCSAN: data-race in pipe_release / pipe_wait_readable

write to 0xffff888121b377f0 of 4 bytes by task 21233 on cpu 1:
 put_pipe_info fs/pipe.c:688 [inline]
 pipe_release+0x186/0x1e0 fs/pipe.c:718
 __fput+0x246/0x4d0 fs/file_table.c:281
 ____fput+0x11/0x20 fs/file_table.c:314
 task_work_run+0x8e/0x110 kernel/task_work.c:141
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:165 [inline]
 exit_to_user_mode_prepare+0x1b2/0x210 kernel/entry/common.c:192
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:267
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888121b377f0 of 4 bytes by task 21236 on cpu 0:
 pipe_lock_nested fs/pipe.c:65 [inline]
 pipe_lock fs/pipe.c:74 [inline]
 pipe_wait_readable+0x1e9/0x230 fs/pipe.c:1032
 splice_from_pipe_next+0x1de/0x260 fs/splice.c:566
 __splice_from_pipe+0xa5/0x4f0 fs/splice.c:624
 vmsplice_to_user fs/splice.c:1268 [inline]
 do_vmsplice+0x109/0x370 fs/splice.c:1346
 __do_sys_vmsplice fs/splice.c:1367 [inline]
 __se_sys_vmsplice+0x13d/0x1c0 fs/splice.c:1349
 __x64_sys_vmsplice+0x51/0x60 fs/splice.c:1349
 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: 0 PID: 21236 Comm: syz-executor.0 Not tainted 5.9.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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