KCSAN: data-race in pipe_unlock / put_pipe

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in pipe_unlock / put_pipe_info fs				2	1908d	1913d	0/28	closed as invalid on 2019/11/19 14:44

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BUG: KCSAN: data-race in pipe_unlock / put_pipe_info

read to 0xffff888121f07f50 of 4 bytes by task 24255 on cpu 1:
 pipe_unlock+0x22/0x60 fs/pipe.c:79
 vmsplice_to_pipe fs/splice.c:1324 [inline]
 do_vmsplice.part.0+0xcc/0x210 fs/splice.c:1370
 do_vmsplice fs/splice.c:1366 [inline]
 __do_sys_vmsplice+0x15f/0x1c0 fs/splice.c:1393
 __se_sys_vmsplice fs/splice.c:1375 [inline]
 __x64_sys_vmsplice+0x5e/0x80 fs/splice.c:1375
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff888121f07f50 of 4 bytes by task 24252 on cpu 0:
 put_pipe_info+0x4d/0xb0 fs/pipe.c:665
 pipe_release+0x115/0x170 fs/pipe.c:693
 __fput+0x1e1/0x520 fs/file_table.c:280
 ____fput+0x1f/0x30 fs/file_table.c:313
 task_work_run+0xf6/0x130 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 24252 Comm: syz-executor.2 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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