syzbot

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BUG: KCSAN: data-race in pipe_lock / put_pipe_info

write to 0xffff888104e735ac of 4 bytes by task 4620 on cpu 1:
 put_pipe_info+0x3d/0xe0 fs/pipe.c:688
 pipe_release+0x15e/0x170 fs/pipe.c:718
 __fput+0x25b/0x4e0 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0xae/0x130 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x156/0x190 kernel/entry/common.c:209
 __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+0x49/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888104e735ac of 4 bytes by task 4638 on cpu 0:
 pipe_lock_nested fs/pipe.c:65 [inline]
 pipe_lock+0x13/0x40 fs/pipe.c:74
 vmsplice_to_pipe fs/splice.c:1255 [inline]
 __do_sys_vmsplice fs/splice.c:1322 [inline]
 __se_sys_vmsplice+0x264/0x940 fs/splice.c:1296
 __x64_sys_vmsplice+0x51/0x60 fs/splice.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000002 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4638 Comm: syz-executor.5 Tainted: G        W         5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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