KCSAN: data-race in pipe_lock / pipe

KCSAN: data-race in pipe_lock / pipe_release (2)
Status: auto-closed as invalid on 2020/10/06 00:08
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 419d, last: 419d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in pipe_lock / pipe_release (4)	1	210d	210d	0/22	auto-closed as invalid on 2021/05/02 03:19
upstream	KCSAN: data-race in pipe_lock / pipe_release	2	476d	493d	0/22	auto-closed as invalid on 2020/08/09 18:16
upstream	KCSAN: data-race in pipe_lock / pipe_release (3)	1	368d	368d	0/22	auto-closed as invalid on 2020/11/25 12:55

Sample crash report:

==================================================================
BUG: KCSAN: data-race in pipe_lock / pipe_release

write to 0xffff88808a98b970 of 4 bytes by task 8204 on cpu 0:
 put_pipe_info fs/pipe.c:707 [inline]
 pipe_release+0x186/0x1e0 fs/pipe.c:737
 __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:140 [inline]
 exit_to_user_mode_prepare+0x1b2/0x210 kernel/entry/common.c:167
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:242
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88808a98b970 of 4 bytes by task 8208 on cpu 1:
 pipe_lock_nested fs/pipe.c:65 [inline]
 pipe_lock+0x13/0x40 fs/pipe.c:74
 do_splice+0xc98/0x10c0 fs/splice.c:1170
 __do_sys_splice fs/splice.c:1419 [inline]
 __se_sys_splice fs/splice.c:1401 [inline]
 __x64_sys_splice+0xf2/0x190 fs/splice.c:1401
 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: 8208 Comm: syz-executor.2 Not tainted 5.9.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2020/09/01 00:01	upstream	b51594df17d0	d5a3ae1f	.config	log	report