syzbot


KCSAN: data-race in lookup_fast / vfs_rename (3)

Status: auto-closed as invalid on 2021/12/24 12:08
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 312d, last: 312d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in lookup_fast / vfs_rename 2 788d 792d 0/24 auto-closed as invalid on 2020/09/04 03:18
upstream KCSAN: data-race in lookup_fast / vfs_rename (4) 1 186d 186d 0/24 auto-closed as invalid on 2022/04/28 23:59
upstream KCSAN: data-race in lookup_fast / vfs_rename (2) 1 590d 590d 0/24 auto-closed as invalid on 2021/03/20 21:45

Sample crash report:
==================================================================
BUG: KCSAN: data-race in lookup_fast / vfs_rename

write to 0xffff888138b9a0c0 of 4 bytes by task 1911 on cpu 0:
 dont_mount include/linux/dcache.h:358 [inline]
 vfs_rename+0xbda/0xe00 fs/namei.c:4636
 do_renameat2+0x6d7/0xa20 fs/namei.c:4777
 __do_sys_rename fs/namei.c:4823 [inline]
 __se_sys_rename fs/namei.c:4821 [inline]
 __x64_sys_rename+0x58/0x60 fs/namei.c:4821
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888138b9a0c0 of 4 bytes by task 1439 on cpu 1:
 d_revalidate fs/namei.c:853 [inline]
 lookup_fast+0x172/0x360 fs/namei.c:1606
 open_last_lookups fs/namei.c:3319 [inline]
 path_openat+0x489/0x1eb0 fs/namei.c:3556
 do_filp_open+0x105/0x220 fs/namei.c:3586
 do_sys_openat2+0xb5/0x2b0 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_sys_openat fs/open.c:1244 [inline]
 __se_sys_openat fs/open.c:1239 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1239
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00400008 -> 0x00008108

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1439 Comm: udevd Not tainted 5.16.0-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 2021/11/19 12:06 upstream 4c388a8e740d 31a30fc0 .config log report info KCSAN: data-race in lookup_fast / vfs_rename
* Struck through repros no longer work on HEAD.