syzbot


KCSAN: data-race in __d_lookup_done / __dentry_kill (2)

Status: auto-closed as invalid on 2020/08/18 04:12
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 831d, last: 812d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (5) 5 488d 523d 0/24 auto-closed as invalid on 2021/07/08 04:16
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (3) 1 730d 730d 0/24 auto-closed as invalid on 2020/11/08 00:33
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (4) 3 609d 633d 0/24 auto-closed as invalid on 2021/03/09 07:41
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (6) 1 163d 163d 0/24 auto-closed as invalid on 2022/05/29 05:25
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill 29 898d 1072d 0/24 auto-closed as invalid on 2020/06/18 14:14

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __d_lookup_done / __dentry_kill

write to 0xffff8880baf90b40 of 4 bytes by task 19138 on cpu 0:
 __d_lookup_done+0x8e/0x240 fs/dcache.c:2648
 __d_add+0x31e/0x450 fs/dcache.c:2668
 d_add+0x41/0x50 fs/dcache.c:2701
 simple_lookup+0x85/0x90 fs/libfs.c:72
 lookup_open fs/namei.c:3074 [inline]
 open_last_lookups fs/namei.c:3169 [inline]
 path_openat+0xa6e/0x20e0 fs/namei.c:3357
 do_filp_open+0xbd/0x1d0 fs/namei.c:3387
 do_sys_openat2+0x33c/0x4a0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 ksys_open include/linux/syscalls.h:1388 [inline]
 __do_sys_open fs/open.c:1201 [inline]
 __se_sys_open fs/open.c:1199 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1199
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880baf90b40 of 4 bytes by task 4488 on cpu 1:
 dentry_unlist fs/dcache.c:544 [inline]
 __dentry_kill+0x1ef/0x450 fs/dcache.c:575
 dentry_kill fs/dcache.c:692 [inline]
 dput+0x208/0x420 fs/dcache.c:878
 handle_mounts fs/namei.c:1389 [inline]
 step_into+0x448/0xe70 fs/namei.c:1690
 open_last_lookups fs/namei.c:3192 [inline]
 path_openat+0xfca/0x20e0 fs/namei.c:3357
 do_filp_open+0xbd/0x1d0 fs/namei.c:3387
 do_sys_openat2+0x33c/0x4a0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 ksys_open include/linux/syscalls.h:1388 [inline]
 __do_sys_open fs/open.c:1201 [inline]
 __se_sys_open fs/open.c:1199 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1199
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4488 Comm: syz-executor.4 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/07/14 04:12 upstream 0dc589da873b ce4c95b3 .config log report
ci2-upstream-kcsan-gce 2020/07/06 05:32 upstream 45a5ac7a5cc3 22f87567 .config log report
ci2-upstream-kcsan-gce 2020/07/01 21:11 upstream edb543cfe5db 695ef2dd .config log report
ci2-upstream-kcsan-gce 2020/06/24 12:08 upstream 3e08a95294a4 41694dbf .config log report
* Struck through repros no longer work on HEAD.