KCSAN: data-race in dput / vfs

KCSAN: data-race in dput / vfs_rename (5)
Status: auto-closed as invalid on 2021/04/14 19:39
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 253d, last: 194d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in dput / vfs_rename (4)	1	346d	346d	0/22	auto-closed as invalid on 2020/11/13 11:07
upstream	KCSAN: data-race in dput / vfs_rename (3)	2	437d	458d	0/22	auto-closed as invalid on 2020/08/14 12:58
upstream	KCSAN: data-race in dput / vfs_rename (2)	1	551d	551d	0/22	auto-closed as invalid on 2020/05/27 13:23
upstream	KCSAN: data-race in dput / vfs_rename	1	660d	660d	0/22	auto-closed as invalid on 2020/02/09 03:47

Sample crash report:

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

write to 0xffff88800cd61cc0 of 4 bytes by task 10321 on cpu 0:
 dont_mount include/linux/dcache.h:357 [inline]
 vfs_rename+0xcb1/0xde0 fs/namei.c:4562
 do_renameat2+0x658/0x990 fs/namei.c:4707
 __do_sys_rename fs/namei.c:4756 [inline]
 __se_sys_rename fs/namei.c:4754 [inline]
 __x64_sys_rename+0x58/0x60 fs/namei.c:4754
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88800cd61cc0 of 4 bytes by task 10344 on cpu 1:
 fast_dput fs/dcache.c:747 [inline]
 dput+0x34/0x430 fs/dcache.c:873
 path_put fs/namei.c:546 [inline]
 terminate_walk+0x109/0x270 fs/namei.c:643
 path_openat+0x18dc/0x21b0 fs/namei.c:3499
 do_filp_open+0xbd/0x1d0 fs/namei.c:3525
 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+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10344 Comm: systemd-udevd Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (5):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/03/10 19:33	upstream	05a59d79793d	764067f3	.config	log	report	info	KCSAN: data-race in dput / vfs_rename
ci2-upstream-kcsan-gce	2021/02/13 23:05	upstream	ac30d8ce28d6	98682e5e	.config	log	report	info	KCSAN: data-race in dput / vfs_rename
ci2-upstream-kcsan-gce	2021/01/27 12:46	upstream	2ab38c17aac1	a0ebf917	.config	log	report	info	KCSAN: data-race in dput / vfs_rename
ci2-upstream-kcsan-gce	2021/01/23 10:24	upstream	fe75a21824e7	52e37319	.config	log	report	info	KCSAN: data-race in dput / vfs_rename
ci2-upstream-kcsan-gce	2021/01/10 19:55	upstream	2ff90100ace8	2c1f2513	.config	log	report	info