syzbot


KCSAN: data-race in lookup_fast / vfs_rename (4)

Status: auto-closed as invalid on 2022/04/28 23:59
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 186d, last: 186d
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 (3) 1 312d 312d 0/24 auto-closed as invalid on 2021/12/24 12:08
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 0xffff8881275e6840 of 4 bytes by task 1813 on cpu 1:
 dont_mount include/linux/dcache.h:348 [inline]
 vfs_rename+0xb06/0xd20 fs/namei.c:4687
 do_renameat2+0x6d7/0xa20 fs/namei.c:4828
 __do_sys_rename fs/namei.c:4874 [inline]
 __se_sys_rename fs/namei.c:4872 [inline]
 __x64_sys_rename+0x58/0x60 fs/namei.c:4872
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881275e6840 of 4 bytes by task 2057 on cpu 0:
 d_revalidate fs/namei.c:853 [inline]
 lookup_fast+0x172/0x360 fs/namei.c:1656
 walk_component+0x6d/0x360 fs/namei.c:2016
 lookup_last fs/namei.c:2475 [inline]
 path_lookupat+0x12d/0x3d0 fs/namei.c:2499
 filename_lookup+0x130/0x310 fs/namei.c:2528
 user_path_at_empty+0x3e/0x110 fs/namei.c:2851
 user_path_at include/linux/namei.h:57 [inline]
 path_setxattr+0x5f/0x190 fs/xattr.c:590
 __do_sys_lsetxattr fs/xattr.c:618 [inline]
 __se_sys_lsetxattr fs/xattr.c:614 [inline]
 __x64_sys_lsetxattr+0x66/0x80 fs/xattr.c:614
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00600008 -> 0x00008108

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2057 Comm: udevd Not tainted 5.17.0-syzkaller-07593-g52deda9551a0-dirty #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 2022/03/24 23:50 upstream 52deda9551a0 89bc8608 .config log report info KCSAN: data-race in lookup_fast / vfs_rename
* Struck through repros no longer work on HEAD.