KCSAN: data-race in d_delete / step_into_slowpath

Status: moderation: reported on 2025/12/04 05:22
Subsystems: fs
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+b33915cb4c9e1c5692ec@syzkaller.appspotmail.com
First crash: 235d, last: 1d01h
✨ AI Jobs (4)
ID Workflow Result Correct Bug Created Started Finished Revision Error
1f31c08a assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ✅ VMHostTrigger: ❌ KCSAN: data-race in d_delete / step_into_slowpath 2026/05/16 03:39 2026/05/16 03:39 2026/05/16 03:41 efdaf0f9

			
		
0f9f77f3 repro KCSAN: data-race in d_delete / step_into_slowpath 2026/03/07 20:08 2026/03/07 20:08 2026/03/07 20:14 31e9c887

			
		
d9fb51b2 assessment-kcsan Benign: ✅ Confident: ✅ KCSAN: data-race in d_delete / step_into_slowpath 2026/02/24 20:27 2026/02/24 20:27 2026/02/24 20:31 305c0ec5

			
		
cb73198d assessment-kcsan 💥 KCSAN: data-race in d_delete / step_into_slowpath 2026/01/10 02:53 2026/01/10 02:53 2026/01/10 02:53 75199160
Error 429, Message: You exceeded your current quota, please check your plan and billing details. For more information on this error, head to: https://ai.google.dev/gemini-api/docs/rate-limits. To moni...
truncated to first 200 bytes; open job for full error

Sample crash report:
==================================================================
BUG: KCSAN: data-race in d_delete / step_into_slowpath

read-write to 0xffff888107b790c0 of 4 bytes by task 4391 on cpu 0:
 d_delete+0x15a/0x180 fs/dcache.c:2694
 d_delete_notify+0x32/0x100 include/linux/fsnotify.h:379
 vfs_unlink+0x287/0x490 fs/namei.c:5530
 filename_unlinkat+0x1dc/0x410 fs/namei.c:5585
 __do_sys_unlink fs/namei.c:5620 [inline]
 __se_sys_unlink+0x2b/0xe0 fs/namei.c:5617
 __x64_sys_unlink+0x1f/0x30 fs/namei.c:5617
 x64_sys_call+0x2eb6/0x3020 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888107b790c0 of 4 bytes by task 2983 on cpu 1:
 d_managed include/linux/dcache.h:433 [inline]
 handle_mounts fs/namei.c:1738 [inline]
 step_into_slowpath+0xea/0x4c0 fs/namei.c:2104
 step_into fs/namei.c:2152 [inline]
 walk_component fs/namei.c:2288 [inline]
 lookup_last fs/namei.c:2789 [inline]
 path_lookupat+0x2eb/0x4c0 fs/namei.c:2813
 filename_lookup+0x18f/0x390 fs/namei.c:2842
 do_readlinkat+0x74/0x2f0 fs/stat.c:571
 __do_sys_readlink fs/stat.c:605 [inline]
 __se_sys_readlink fs/stat.c:602 [inline]
 __x64_sys_readlink+0x47/0x60 fs/stat.c:602
 x64_sys_call+0x2b51/0x3020 arch/x86/include/generated/asm/syscalls_64.h:90
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00300180 -> 0x00004080

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2983 Comm: udevd Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
==================================================================

Crashes (113):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/26 09:15 upstream 3dab139d4795 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/25 17:31 upstream 0ce37745d4bf 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/25 15:19 upstream e2a936998ab2 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/23 14:16 upstream 4539944e5151 71a13572 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/22 16:26 upstream 248951ddc14d 4a865b71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/22 03:20 upstream 248951ddc14d b561ce9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/21 07:36 upstream b95f03f04d47 de6a700d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/20 19:09 upstream 1590cf032971 de6a700d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/17 23:13 upstream 111e7b23e5b0 8aaff637 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/16 12:15 upstream 37e2f878a7a6 71b49442 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/15 14:22 upstream 58717b2a1365 a4ed0f4f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/13 03:14 upstream f4fb100039e9 d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/12 06:37 upstream 44696aa3a489 d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/11 17:25 upstream dd3210c47e8d d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/09 12:00 upstream 0e35b9b6ec0f a0c310a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/02 10:44 upstream 4a50a141f05a 27192279 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/01 09:10 upstream 665159e24674 00a5cf1c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/07/01 01:49 upstream dc59e4fea9d8 00e8b0fd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/26 04:04 upstream a142da0b2d32 7ff32d8b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/23 08:18 upstream 502d801f0ab0 5a630be6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/23 03:19 upstream 1dc18801be29 5a630be6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/22 07:40 upstream ef0c9f75a195 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/15 08:45 upstream 95e56f0f293e 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/13 19:58 upstream 062871f1371b 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/12 09:55 upstream 2b414a95b8f7 e93da63e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/09 11:15 upstream 2d3090a8aeb5 c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/08 12:22 upstream 4549871118cf cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/04 23:26 upstream 9154c4af7829 197909be .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/04 16:44 upstream ba3e43a9e601 197909be .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/06/02 10:37 upstream 6f3ed7fec72f 1095583b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/30 21:31 upstream f5e5d3509bff 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/28 09:51 upstream eb3f4b7426cf 4c36e7e5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/26 21:24 upstream d60ec36cab33 2b01f00e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/26 12:05 upstream e8c2f9fdadee a3e47276 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/24 15:53 upstream 4cbfe4502e3d c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/22 17:12 upstream 45255ea1ca09 5f091fcc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/21 12:10 upstream 8bc67e4db64a e195359d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/20 15:30 upstream 27fa82620cba 62fb93a2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/20 04:32 upstream 27fa82620cba 0909d65f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/11 00:24 upstream 5d6919055dec 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/10 20:51 upstream 1bfaee9d3351 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/07 23:23 upstream 8ab992f815d6 cbf9e0fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/05/01 11:11 upstream 26fd6bff2c05 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/04/30 18:51 upstream e75a43c7cec4 a7464baf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/04/30 11:52 upstream e75a43c7cec4 a7464baf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/03/05 02:28 upstream ecc64d2dc9ff a9fe5c9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/02/24 14:39 upstream 7dff99b35460 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2026/01/09 15:51 upstream 623fb9912f6a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
2025/12/04 05:21 upstream 8f7aa3d3c732 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / step_into_slowpath
* Struck through repros no longer work on HEAD.