syzbot


KCSAN: data-race in path_openat / shrink_dentry_list

Status: auto-closed as invalid on 2022/06/06 20:05
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 214d, last: 214d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in path_openat / shrink_dentry_list (2) 1 148d 148d 0/24 auto-closed as invalid on 2022/08/12 10:46

Sample crash report:
==================================================================
BUG: KCSAN: data-race in path_openat / shrink_dentry_list

read-write to 0xffff8881387213c0 of 4 bytes by task 9739 on cpu 0:
 d_shrink_del fs/dcache.c:448 [inline]
 shrink_dentry_list+0x1cf/0x380 fs/dcache.c:1188
 shrink_dcache_sb+0x188/0x2d0 fs/dcache.c:1321
 reconfigure_super+0x146/0x540 fs/super.c:888
 do_remount fs/namespace.c:2702 [inline]
 path_mount+0x984/0xb60 fs/namespace.c:3362
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x281/0x2d0 fs/namespace.c:3568
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3568
 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 0xffff8881387213c0 of 4 bytes by task 1827 on cpu 1:
 __d_entry_type include/linux/dcache.h:385 [inline]
 d_is_reg include/linux/dcache.h:420 [inline]
 do_open fs/namei.c:3468 [inline]
 path_openat+0x1592/0x1b30 fs/namei.c:3609
 do_filp_open+0x105/0x220 fs/namei.c:3636
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1213
 do_sys_open fs/open.c:1229 [inline]
 __do_sys_openat fs/open.c:1245 [inline]
 __se_sys_openat fs/open.c:1240 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1240
 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: 0x00280400 -> 0x00200000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1827 Comm: syz-executor.4 Not tainted 5.18.0-rc5-syzkaller-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 2022/05/02 20:03 upstream 672c0c517342 2df221f6 .config log report info KCSAN: data-race in path_openat / shrink_dentry_list
* Struck through repros no longer work on HEAD.