KCSAN: data-race in pipe_wait / put_pipe

KCSAN: data-race in pipe_wait / put_pipe_info (3)
Status: closed as invalid on 2020/06/18 14:24
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 452d, last: 449d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in pipe_wait / put_pipe_info (2)				41	540d	618d	0/22	auto-closed as invalid on 2020/04/16 02:24
upstream	KCSAN: data-race in pipe_wait / put_pipe_info				34	620d	652d	0/22	closed as invalid on 2019/11/19 14:04

Sample crash report:

==================================================================
BUG: KCSAN: data-race in pipe_wait / put_pipe_info

write to 0xffff88809b1898a8 of 4 bytes by task 22608 on cpu 0:
 put_pipe_info+0x47/0xb0 fs/pipe.c:704
 pipe_release+0x150/0x1a0 fs/pipe.c:734
 __fput+0x1e9/0x500 fs/file_table.c:280
 ____fput+0x1b/0x30 fs/file_table.c:313
 task_work_run+0xba/0x120 kernel/task_work.c:123
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2ae/0x2c0 arch/x86/entry/common.c:165
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x38b/0x3b0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88809b1898a8 of 4 bytes by task 22603 on cpu 1:
 pipe_lock_nested fs/pipe.c:64 [inline]
 pipe_lock fs/pipe.c:73 [inline]
 pipe_wait+0x153/0x1b0 fs/pipe.c:124
 splice_from_pipe_next.part.0+0x7d/0x1c0 fs/splice.c:576
 splice_from_pipe_next fs/splice.c:555 [inline]
 __splice_from_pipe+0xbd/0x4a0 fs/splice.c:634
 vmsplice_to_user fs/splice.c:1294 [inline]
 do_vmsplice.part.0+0x1c8/0x210 fs/splice.c:1372
 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+0x59/0x70 fs/splice.c:1375
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 22603 Comm: syz-executor.1 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2020/05/06 13:14	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	4618eb2d	.config	log	report
ci2-upstream-kcsan-gce	2020/05/04 07:29	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	58ae5e18	.config	log	report