KCSAN: data-race in __dentry_kill / lookup

KCSAN: data-race in __dentry_kill / lookup_fast (4)
Status: auto-closed as invalid on 2021/03/06 20:57
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 263d, last: 238d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __dentry_kill / lookup_fast (5)	12	117d	190d	0/22	auto-closed as invalid on 2021/07/05 09:49
upstream	KCSAN: data-race in __dentry_kill / lookup_fast (2)	5	398d	458d	0/22	auto-closed as invalid on 2020/09/27 09:27
upstream	KCSAN: data-race in __dentry_kill / lookup_fast	10	481d	574d	0/22	closed as invalid on 2020/06/18 14:24
upstream	KCSAN: data-race in __dentry_kill / lookup_fast (3)	3	300d	292d	0/22	auto-closed as invalid on 2021/01/03 16:37

Sample crash report:

==================================================================
BUG: KCSAN: data-race in __dentry_kill / lookup_fast

write to 0xffff88810d5d8a80 of 4 bytes by task 17137 on cpu 1:
 dentry_unlist fs/dcache.c:519 [inline]
 __dentry_kill+0x147/0x450 fs/dcache.c:575
 dentry_kill fs/dcache.c:692 [inline]
 dput+0x208/0x420 fs/dcache.c:885
 do_renameat2+0x5cf/0x900 fs/namei.c:4461
 __do_sys_rename fs/namei.c:4508 [inline]
 __se_sys_rename fs/namei.c:4506 [inline]
 __x64_sys_rename+0x58/0x60 fs/namei.c:4506
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810d5d8a80 of 4 bytes by task 4878 on cpu 0:
 d_revalidate fs/namei.c:767 [inline]
 lookup_fast+0x15f/0x370 fs/namei.c:1493
 open_last_lookups fs/namei.c:3146 [inline]
 path_openat+0x45e/0x20a0 fs/namei.c:3368
 do_filp_open+0xbd/0x1d0 fs/namei.c:3398
 do_sys_openat2+0xa3/0x250 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_open fs/open.c:1196 [inline]
 __se_sys_open fs/open.c:1192 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1192
 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: 0 PID: 4878 Comm: systemd-journal Not tainted 5.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/01/30 20:53	upstream	0e9bcda5d286	fc9fd31e	.config	log	report	info	KCSAN: data-race in __dentry_kill / lookup_fast
ci2-upstream-kcsan-gce	2021/01/23 05:44	upstream	83d09ad4b950	52e37319	.config	log	report	info	KCSAN: data-race in __dentry_kill / lookup_fast
ci2-upstream-kcsan-gce	2021/01/05 20:18	upstream	36bbbd0e234d	a0234d98	.config	log	report	info