syzbot

 sign-in | mailing list | source | docs
🐞 Open [1407]
≡ Subsystems
🐞 Fixed [6991]
🐞 Invalid [18240]
⬇ Missing Backports [223]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
✨ AI
💬 Send us feedback

KCSAN: data-race in __dentry_kill / lookup_fast (8)

Status: auto-obsoleted due to no activity on 2023/05/25 00:07
Subsystems: fs
[Documentation on labels]
First crash: 1125d, last: 1062d
▶ ▼ Similar bugs (14)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dentry_kill / lookup_fast (5) fs 6 12 1751d 1823d 0/29 auto-closed as invalid on 2021/07/05 09:49
upstream KCSAN: data-race in __dentry_kill / lookup_fast (13) fs 6 5 337d 385d 0/29 auto-obsoleted due to no activity on 2025/06/08 21:40
upstream KCSAN: data-race in __dentry_kill / lookup_fast (2) fs 6 5 2032d 2092d 0/29 auto-closed as invalid on 2020/09/27 09:27
upstream KCSAN: data-race in __dentry_kill / lookup_fast fs 6 10 2114d 2208d 0/29 closed as invalid on 2020/06/18 14:24
upstream KCSAN: data-race in __dentry_kill / lookup_fast (11) fs 6 1 605d 605d 0/29 auto-obsoleted due to no activity on 2024/08/23 20:28
upstream KCSAN: data-race in __dentry_kill / lookup_fast (10) fs 6 3 716d 753d 0/29 auto-obsoleted due to no activity on 2024/05/05 12:07
upstream KCSAN: data-race in __dentry_kill / lookup_fast (12) fs 6 3 442d 495d 0/29 auto-obsoleted due to no activity on 2025/02/24 08:27
upstream KCSAN: data-race in __dentry_kill / lookup_fast (14) fs 6 1 206d 206d 0/29 auto-obsoleted due to no activity on 2025/10/18 05:13
upstream KCSAN: data-race in __dentry_kill / lookup_fast (7) fs 6 27 1172d 1433d 0/29 auto-obsoleted due to no activity on 2023/02/12 11:35
upstream KCSAN: data-race in __dentry_kill / lookup_fast (15) race:benign fs 6 8 7d19h 51d 0/29 moderation: reported on 2026/01/25 03:24
upstream KCSAN: data-race in __dentry_kill / lookup_fast (6) fs 6 1 1578d 1578d 0/29 auto-closed as invalid on 2021/12/25 02:52
upstream KCSAN: data-race in __dentry_kill / lookup_fast (4) fs 6 3 1871d 1896d 0/29 auto-closed as invalid on 2021/03/06 20:57
upstream KCSAN: data-race in __dentry_kill / lookup_fast (3) fs 6 3 1933d 1926d 0/29 auto-closed as invalid on 2021/01/03 16:37
upstream KCSAN: data-race in __dentry_kill / lookup_fast (9) fs 6 31 794d 829d 0/29 auto-obsoleted due to no activity on 2024/02/17 10:11

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

read-write to 0xffff88814e232e40 of 4 bytes by task 29009 on cpu 0:
 dentry_unlist fs/dcache.c:547 [inline]
 __dentry_kill+0x18f/0x4a0 fs/dcache.c:603
 dentry_kill+0x8d/0x1e0
 dput+0x118/0x1f0 fs/dcache.c:913
 do_unlinkat+0x28d/0x4f0 fs/namei.c:4319
 __do_sys_unlink fs/namei.c:4364 [inline]
 __se_sys_unlink fs/namei.c:4362 [inline]
 __x64_sys_unlink+0x30/0x40 fs/namei.c:4362
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88814e232e40 of 4 bytes by task 2746 on cpu 1:
 d_revalidate fs/namei.c:856 [inline]
 lookup_fast+0xd9/0x290 fs/namei.c:1635
 walk_component+0x3f/0x230 fs/namei.c:1990
 lookup_last fs/namei.c:2451 [inline]
 path_lookupat+0x10a/0x2a0 fs/namei.c:2475
 filename_lookup+0x126/0x300 fs/namei.c:2504
 user_path_at_empty+0x42/0x110 fs/namei.c:2877
 do_readlinkat+0x92/0x210 fs/stat.c:477
 __do_sys_readlink fs/stat.c:510 [inline]
 __se_sys_readlink fs/stat.c:507 [inline]
 __x64_sys_readlink+0x47/0x50 fs/stat.c:507
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00600008 -> 0x00008008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2746 Comm: udevd Not tainted 6.3.0-rc7-syzkaller-00060-g789b4a41c247 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
==================================================================

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/04/20 00:01 upstream 789b4a41c247 a219f34e .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2023/04/16 09:41 upstream a7a55e27ad72 ec410564 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2023/04/15 01:03 upstream 95abc817ab3a ec410564 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2023/04/07 08:38 upstream f2afccfefe7b 00ce4c67 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2023/04/02 09:39 upstream 00c7b5f4ddc5 f325deb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2023/03/18 19:51 upstream 478a351ce0d6 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2023/03/04 21:45 upstream 0988a0ea7919 f8902b57 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2023/02/15 16:20 upstream e1c04510f521 6be0f1f5 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
* Struck through repros no longer work on HEAD.