syzbot


KCSAN: data-race in d_delete / path_lookupat

Status: moderation: reported on 2025/12/10 11:32
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+36776ef3c8bacad09f26@syzkaller.appspotmail.com
First crash: 96d, last: 2h26m
✨ AI Jobs (3)
ID Workflow Result Correct Bug Created Started Finished Revision Error
c991cba9-d380-467f-a667-d1e705568d1e repro KCSAN: data-race in d_delete / path_lookupat 2026/03/08 09:29 2026/03/08 09:29 2026/03/08 09:30 31e9c887f7dc24e04b3ca70d0d54fc34141844b0
80045fc5-894c-4f01-ba81-6a303df75dcb assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in d_delete / path_lookupat 2026/02/24 23:00 2026/02/24 23:00 2026/02/24 23:10 305c0ec5cd886e2d13738e28e1b2df9b0ec20fc9
49a2c9c6-3a40-4bf1-b1b1-8ee751e6e60e assessment-kcsan 💥 KCSAN: data-race in d_delete / path_lookupat 2026/01/10 06:25 2026/01/10 06:25 2026/01/10 06:44 7519916073b761ced56a7b15fdeeb4674e8dc125 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 monitor your current usage, head to: https://ai.dev/rate-limit. * Quota exceeded for metric: generativelanguage.googleapis.com/generate_requests_per_model_per_day, limit: 0, Status: RESOURCE_EXHAUSTED, Details: [map[@type:type.googleapis.com/google.rpc.Help links:[map[description:Learn more about Gemini API quotas url:https://ai.google.dev/gemini-api/docs/rate-limits]]] map[@type:type.googleapis.com/google.rpc.QuotaFailure violations:[map[quotaId:GenerateRequestsPerDayPerProjectPerModel quotaMetric:generativelanguage.googleapis.com/generate_requests_per_model_per_day]]] map[@type:type.googleapis.com/google.rpc.DebugInfo detail:[ORIGINAL ERROR] generic::resource_exhausted: 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 monitor your current usage, head to: https://ai.dev/rate-limit. * Quota exceeded for metric: generativelanguage.googleapis.com/generate_requests_per_model_per_day, limit: 0 [google.rpc.error_details_ext] { 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 monitor your current usage, head to: https://ai.dev/rate-limit. \n* Quota exceeded for metric: generativelanguage.googleapis.com/generate_requests_per_model_per_day, limit: 0" details { type_url: "type.googleapis.com/language_labs.genai.debug.GeminiApiDebugInfo" value: "RM\nK\nEgenerativelanguage.googleapis.com/generate_requests_per_model_per_day\030\000\"\000" } details { [type.googleapis.com/google.rpc.Help] { links { description: "Learn more about Gemini API quotas" url: "https://ai.google.dev/gemini-api/docs/rate-limits" } } } details { [type.googleapis.com/google.rpc.QuotaFailure] { violations { quota_metric: "generativelanguage.googleapis.com/generate_requests_per_model_per_day" quota_id: "GenerateRequestsPerDayPerProjectPerModel" } } } }]]

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

read-write to 0xffff88811b306300 of 4 bytes by task 7972 on cpu 1:
 d_delete+0xbe/0xe0 fs/dcache.c:2529
 d_delete_notify+0x32/0x100 include/linux/fsnotify.h:375
 vfs_unlink+0x289/0x490 fs/namei.c:5485
 filename_unlinkat+0x1e2/0x410 fs/namei.c:5540
 __do_sys_unlink fs/namei.c:5575 [inline]
 __se_sys_unlink+0x2b/0xe0 fs/namei.c:5572
 __x64_sys_unlink+0x1f/0x30 fs/namei.c:5572
 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+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811b306300 of 4 bytes by task 3001 on cpu 0:
 d_managed include/linux/dcache.h:403 [inline]
 step_into fs/namei.c:2136 [inline]
 walk_component fs/namei.c:2285 [inline]
 lookup_last fs/namei.c:2780 [inline]
 path_lookupat+0x1d8/0x500 fs/namei.c:2804
 filename_lookup+0x190/0x390 fs/namei.c:2833
 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+0x12c/0x370 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: 0 UID: 0 PID: 3001 Comm: udevd Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================

Crashes (17):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/17 07:15 upstream 2d1373e4246d 0737c18f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/03/09 05:33 upstream 014441d1e4b2 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/03/08 03:58 upstream c23719abc330 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/03/06 12:05 upstream 5ee8dbf54602 41d8037d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/03/01 08:31 upstream eb71ab2bf722 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/02/21 13:43 upstream d79526b89571 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/02/14 23:05 upstream 3e48a11675c5 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/02/10 12:24 upstream 72c395024dac 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/02/07 18:29 upstream 2687c848e578 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/02/03 03:22 upstream dee65f79364c d78927dd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/02/01 01:40 upstream ad9a728a3388 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/01/30 12:47 upstream 4d310797262f ae7dc18c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/01/20 02:30 upstream 24d479d26b25 572effc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/01/17 18:20 upstream d3eeb99bbc99 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2026/01/01 12:48 upstream b69053dd3ffb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2025/12/21 13:20 upstream 9094662f6707 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
2025/12/10 11:31 upstream c9b47175e913 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_delete / path_lookupat
* Struck through repros no longer work on HEAD.