syzbot


KCSAN: data-race in drop_nlink / vfs_getattr_nosec (4)

Status: auto-closed as invalid on 2021/11/01 05:59
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 432d, last: 432d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in drop_nlink / vfs_getattr_nosec (6) 1 325d 325d 0/24 auto-closed as invalid on 2022/02/16 06:56
upstream KCSAN: data-race in drop_nlink / vfs_getattr_nosec (3) 2 486d 505d 0/24 auto-closed as invalid on 2021/09/07 16:42
upstream KCSAN: data-race in drop_nlink / vfs_getattr_nosec 1 626d 626d 0/24 auto-closed as invalid on 2021/04/21 10:41
upstream KCSAN: data-race in drop_nlink / vfs_getattr_nosec (5) 1 388d 388d 0/24 auto-closed as invalid on 2021/12/15 06:52
upstream KCSAN: data-race in drop_nlink / vfs_getattr_nosec (2) 6 553d 585d 0/24 auto-closed as invalid on 2021/07/03 10:04

Sample crash report:
==================================================================
BUG: KCSAN: data-race in drop_nlink / vfs_getattr_nosec

write to 0xffff8881099bc240 of 4 bytes by task 30799 on cpu 0:
 drop_nlink+0x37/0x90 fs/inode.c:309
 shmem_unlink+0x1ab/0x1d0 mm/shmem.c:2933
 shmem_rename2+0x2fd/0x440 mm/shmem.c:3029
 vfs_rename+0x9d9/0xe20 fs/namei.c:4628
 do_renameat2+0x6d7/0xa20 fs/namei.c:4779
 __do_sys_rename fs/namei.c:4825 [inline]
 __se_sys_rename fs/namei.c:4823 [inline]
 __x64_sys_rename+0x58/0x60 fs/namei.c:4823
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881099bc240 of 4 bytes by task 30801 on cpu 1:
 generic_fillattr fs/stat.c:49 [inline]
 vfs_getattr_nosec+0x1c1/0x2f0 fs/stat.c:126
 vfs_getattr fs/stat.c:160 [inline]
 vfs_statx+0x138/0x2a0 fs/stat.c:225
 vfs_fstatat fs/stat.c:243 [inline]
 vfs_lstat include/linux/fs.h:3356 [inline]
 __do_sys_newlstat fs/stat.c:398 [inline]
 __se_sys_newlstat+0x5d/0x250 fs/stat.c:392
 __x64_sys_newlstat+0x2d/0x40 fs/stat.c:392
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 30801 Comm: systemd-udevd Not tainted 5.15.0-rc2-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 2021/09/27 05:52 upstream 996148ee05d0 78494d16 .config log report info KCSAN: data-race in drop_nlink / vfs_getattr_nosec
* Struck through repros no longer work on HEAD.