KCSAN: data-race in path_openat / vfs

KCSAN: data-race in path_openat / vfs_rename (3)
Status: auto-closed as invalid on 2021/07/04 13:26
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 176d, last: 141d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in path_openat / vfs_rename (2)				1	242d	242d	0/22	auto-closed as invalid on 2021/03/25 02:59
upstream	KCSAN: data-race in path_openat / vfs_rename				1	547d	547d	0/22	closed as invalid on 2020/06/18 14:24

Sample crash report:

==================================================================
BUG: KCSAN: data-race in path_openat / vfs_rename

write to 0xffff8881067dec00 of 4 bytes by task 29247 on cpu 1:
 dont_mount include/linux/dcache.h:358 [inline]
 vfs_rename+0xe4a/0xfb0 fs/namei.c:4551
 do_renameat2+0x59e/0x9b0 fs/namei.c:4696
 __do_sys_rename fs/namei.c:4745 [inline]
 __se_sys_rename fs/namei.c:4743 [inline]
 __x64_sys_rename+0x58/0x60 fs/namei.c:4743
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881067dec00 of 4 bytes by task 1035 on cpu 0:
 __d_entry_type include/linux/dcache.h:395 [inline]
 d_is_reg include/linux/dcache.h:430 [inline]
 do_open fs/namei.c:3353 [inline]
 path_openat+0x16f9/0x20b0 fs/namei.c:3494
 do_filp_open+0xd9/0x1f0 fs/namei.c:3521
 do_sys_openat2+0xa3/0x250 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_open fs/open.c:1211 [inline]
 __se_sys_open fs/open.c:1207 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1207
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00400008 -> 0x00400108

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1035 Comm: systemd-udevd Not tainted 5.13.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (4):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/05/30 13:24	upstream	b90e90f40b4f	325a8dab	.config	log	report	info	KCSAN: data-race in path_openat / vfs_rename
ci2-upstream-kcsan-gce	2021/05/02 20:42	upstream	17ae69aba89d	77e2b668	.config	log	report	info	KCSAN: data-race in path_openat / vfs_rename
ci2-upstream-kcsan-gce	2021/04/26 16:54	upstream	9f4ad9e425a1	805b5003	.config	log	report	info	KCSAN: data-race in path_openat / vfs_rename
ci2-upstream-kcsan-gce	2021/04/24 20:53	upstream	2a1d7946fa53	17f0b706	.config	log	report	info	KCSAN: data-race in path_openat / vfs_rename