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

Status: auto-closed as invalid on 2021/03/08 10:39
Subsystems: fs
[Documentation on labels]
First crash: 2048d, last: 2019d
▶ ▼ Similar bugs (13)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (9) fs 6 1 1183d 1183d 0/29 auto-obsoleted due to no activity on 2023/06/21 20:05
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (6) fs 6 1 1490d 1490d 0/29 auto-closed as invalid on 2022/08/18 12:57
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (4) fs 6 1 1962d 1962d 0/29 auto-closed as invalid on 2021/05/04 09:30
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (10) fs 6 2 934d 936d 0/29 auto-obsoleted due to no activity on 2024/02/25 15:26
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (2) fs 6 1 2112d 2112d 0/29 auto-closed as invalid on 2020/12/05 11:21
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (11) fs 6 2 842d 846d 0/29 auto-obsoleted due to no activity on 2024/05/27 20:04
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (13) fs 6 2 168d 175d 0/29 auto-obsoleted due to no activity on 2026/04/23 02:16
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (8) fs 6 1 1246d 1246d 0/29 auto-obsoleted due to no activity on 2023/04/27 01:35
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (12) fs 6 1 283d 283d 0/29 auto-obsoleted due to no activity on 2025/12/29 01:39
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (7) fs 6 1 1453d 1453d 0/29 auto-closed as invalid on 2022/09/24 23:48
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (5) fs 6 1 1812d 1812d 0/29 auto-closed as invalid on 2021/10/01 10:16
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list (14) race:benign prio:low fs 6 1 35d 35d 0/29 moderation: reported on 2026/07/09 05:16
upstream KCSAN: data-race in lookup_fast / shrink_dentry_list fs 6 3 2169d 2195d 0/29 auto-closed as invalid on 2020/10/08 14:19

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

write to 0xffff88812f2c7780 of 4 bytes by task 13051 on cpu 1:
 d_lru_del fs/dcache.c:410 [inline]
 __dput_to_list fs/dcache.c:898 [inline]
 shrink_dentry_list+0x2e5/0x540 fs/dcache.c:1147
 shrink_dcache_parent+0x4d/0x3f0 fs/dcache.c:1575
 d_invalidate+0x6e/0x1a0 fs/dcache.c:1684
 lookup_fast+0x2ed/0x370 fs/namei.c:1509
 walk_component+0x5c/0x350 fs/namei.c:1857
 link_path_walk+0x491/0x760 fs/namei.c:2182
 path_openat+0x19c/0x20a0 fs/namei.c:3367
 do_filp_open+0xbd/0x1d0 fs/namei.c:3398
 do_sys_openat2+0xa3/0x250 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_open fs/open.c:1196 [inline]
 __se_sys_open fs/open.c:1192 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1192
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812f2c7780 of 4 bytes by task 13045 on cpu 0:
 d_revalidate fs/namei.c:767 [inline]
 lookup_fast+0x7b/0x370 fs/namei.c:1505
 walk_component+0x5c/0x350 fs/namei.c:1857
 link_path_walk+0x491/0x760 fs/namei.c:2182
 path_openat+0x19c/0x20a0 fs/namei.c:3367
 do_filp_open+0xbd/0x1d0 fs/namei.c:3398
 do_sys_openat2+0xa3/0x250 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_open fs/open.c:1196 [inline]
 __se_sys_open fs/open.c:1192 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1192
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13045 Comm: systemd-udevd Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/02/01 10:34 upstream 1048ba83fb1c fc9fd31e .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in lookup_fast / shrink_dentry_list
2021/01/03 07:45 upstream 3516bd729358 79264ae3 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.