KCSAN: data-race in link_path_walk / vfs

KCSAN: data-race in link_path_walk / vfs_rmdir (2)
Status: auto-closed as invalid on 2021/06/17 14:31
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 131d, last: 131d

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in link_path_walk / vfs_rmdir				1	410d	410d	0/22	auto-closed as invalid on 2020/09/11 12:18

Sample crash report:

==================================================================
BUG: KCSAN: data-race in link_path_walk / vfs_rmdir

write to 0xffff888106733840 of 4 bytes by task 10428 on cpu 1:
 dont_mount include/linux/dcache.h:358 [inline]
 vfs_rmdir+0x1ac/0x2c0 fs/namei.c:3901
 do_rmdir+0x14a/0x2e0 fs/namei.c:3958
 __do_sys_rmdir fs/namei.c:3976 [inline]
 __se_sys_rmdir fs/namei.c:3974 [inline]
 __x64_sys_rmdir+0x2c/0x30 fs/namei.c:3974
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888106733840 of 4 bytes by task 10427 on cpu 0:
 link_path_walk+0x37d/0x780 fs/namei.c:2231
 path_parentat fs/namei.c:2473 [inline]
 filename_parentat+0x104/0x950 fs/namei.c:2495
 do_unlinkat+0x59/0x4f0 fs/namei.c:4063
 __do_sys_unlink fs/namei.c:4139 [inline]
 __se_sys_unlink fs/namei.c:4137 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:4137
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10427 Comm: systemd-udevd Not tainted 5.13.0-rc1-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	2021/05/13 14:29	upstream	c06a2ba62fc4	ecb594cb	.config	log	report			info	KCSAN: data-race in link_path_walk / vfs_rmdir