syzbot

 sign-in | mailing list | source | docs
🐞 Open [849]
🐞 Fixed [87]
🐞 Invalid [1244]
⬇ Missing Backports [132]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

INFO: rcu detected stall in gc_worker

Status: upstream: reported C repro on 2023/08/06 21:00
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+c6ab59ecefe93f5cab03@syzkaller.appspotmail.com
First crash: 954d, last: 6d10h
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2023/08/07 upstream (ToT) 52a93d39b17d C [report] INFO: rcu detected stall in corrupted
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in gc_worker (2) netfilter 1 C unreliable 4 1522d 1560d 0/29 closed as invalid on 2022/02/08 10:33
upstream INFO: rcu detected stall in gc_worker (3) netfilter 1 C done done 318 7h01m 1459d 0/29 upstream: reported C repro on 2022/03/20 12:02
upstream INFO: rcu detected stall in gc_worker netfilter 1 8 2526d 2611d 0/29 auto-closed as invalid on 2019/10/14 16:34
linux-6.1 INFO: rcu detected stall in gc_worker origin:lts-only 1 C inconclusive 107 16d 989d 0/3 upstream: reported C repro on 2023/07/03 02:12
linux-4.19 INFO: rcu detected stall in gc_worker 1 syz error 1 1425d 1425d 0/1 upstream: reported syz repro on 2022/04/22 15:43
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/03/07 21:58 11m retest repro linux-5.15.y report log
2026/03/07 21:58 44m retest repro linux-5.15.y report log
2026/03/07 21:58 46m retest repro linux-5.15.y report log
2026/03/07 21:58 20m retest repro linux-5.15.y report log
2026/03/07 21:58 15m retest repro linux-5.15.y report log
2026/03/07 21:02 17m retest repro linux-5.15.y report log
2026/03/07 21:02 13m retest repro linux-5.15.y report log
2026/03/07 20:54 11m retest repro linux-5.15.y report log
2026/03/07 18:13 12m retest repro linux-5.15.y report log
2026/03/07 18:13 16m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (4)
Created Duration User Patch Repo Result
2024/03/16 14:35 18m bisect fix linux-5.15.y error job log
2024/01/19 00:07 2h02m bisect fix linux-5.15.y OK (0) job log log
2023/11/27 09:09 1h53m bisect fix linux-5.15.y OK (0) job log log
2023/10/04 20:45 1h54m bisect fix linux-5.15.y OK (0) job log log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P1108/1:b..l
	(detected by 1, t=10505 jiffies, g=10457, q=1960)
task:kworker/0:2     state:R  running task     stack:25744 pid: 1108 ppid:     2 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:seqcount_lockdep_reader_access+0x196/0x1d0 include/linux/seqlock.h:106
Code: f9 4d 85 e4 75 16 e8 79 ef 54 f9 eb 15 e8 72 ef 54 f9 e8 2d 37 98 01 4d 85 e4 74 ea e8 63 ef 54 f9 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 43 c7 44 3e 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc90004467a20 EFLAGS: 00000293
RAX: ffffffff882431ad RBX: 0000000000000000 RCX: ffff8880215e5940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90004467ad0 R08: ffffffff901d415f R09: 1ffffffff203a82b
R10: dffffc0000000000 R11: fffffbfff203a82c R12: 0000000000000200
R13: ffff8880215b7e18 R14: 1ffff9200088cf44 R15: dffffc0000000000
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:338 [inline]
 gc_worker+0x2e2/0x1390 net/netfilter/nf_conntrack_core.c:1472
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Crashes (129):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/12 02:35 linux-5.15.y 91d48252ad4b 2d88ab01 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in gc_worker
2026/01/06 12:02 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/11/17 05:02 linux-5.15.y cc5ec8769306 f7988ea4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in gc_worker
2025/01/02 09:55 linux-5.15.y 91786f140358 d3ccff63 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2024/10/18 05:59 linux-5.15.y 584a40a22cb9 666f77ed .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2023/08/06 21:00 linux-5.15.y 38d4ca22a528 4ffcc9ef .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/05/04 20:57 linux-5.15.y 16fdf2c7111b b0714e37 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: rcu detected stall in gc_worker
2025/06/04 08:55 linux-5.15.y 98f47d0e9b8c a30356b7 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: soft lockup in gc_worker
2026/02/21 13:49 linux-5.15.y 3330a8d33e08 6e7b5511 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/12/10 16:21 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/11/04 23:23 linux-5.15.y cc5ec8769306 686bf657 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/08/16 16:12 linux-5.15.y c79648372d02 1804e95e .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in gc_worker
2024/11/02 13:59 linux-5.15.y 72244eab0dad f00eed24 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2024/10/30 07:17 linux-5.15.y 74cdd62cb470 66aeb999 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2024/10/16 16:12 linux-5.15.y 3a5928702e71 bde2d81c .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2024/09/27 13:18 linux-5.15.y 3a5928702e71 9314348a .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2024/09/21 03:18 linux-5.15.y 3a5928702e71 6f888b75 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2024/09/06 13:49 linux-5.15.y 14e468424d3e 464ac2ed .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2024/08/31 10:37 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/07/13 05:45 linux-5.15.y 2f693b607545 3cda49cf .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: rcu detected stall in gc_worker
2025/06/29 20:05 linux-5.15.y 3dea0e7f549e fc9d8ee5 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: rcu detected stall in gc_worker
2024/09/20 16:59 linux-5.15.y 3a5928702e71 6f888b75 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: rcu detected stall in gc_worker
2025/08/02 20:11 linux-5.15.y c79648372d02 7368264b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: soft lockup in gc_worker
2025/08/02 15:50 linux-5.15.y c79648372d02 7368264b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: soft lockup in gc_worker
2026/03/07 23:15 linux-5.15.y 91d48252ad4b 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/02/20 05:51 linux-5.15.y 3330a8d33e08 c8d8c52d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/02/18 12:28 linux-5.15.y e45d5d41c134 39751c21 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/02/17 09:35 linux-5.15.y e45d5d41c134 e439b951 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/02/14 18:18 linux-5.15.y e45d5d41c134 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/02/12 14:11 linux-5.15.y e45d5d41c134 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/02/09 07:24 linux-5.15.y 7b232985052f 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/02/08 22:24 linux-5.15.y 7b232985052f 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in gc_worker
2026/02/01 22:49 linux-5.15.y 9eec9a14ee10 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/01/23 06:04 linux-5.15.y 9eec9a14ee10 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in gc_worker
2026/01/23 01:22 linux-5.15.y 9eec9a14ee10 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/01/19 08:06 linux-5.15.y 68efe5a6c16a 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/01/14 06:37 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2026/01/01 09:24 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/12/19 02:11 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/12/15 22:47 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/12/03 21:03 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in gc_worker
2025/11/26 02:21 linux-5.15.y cc5ec8769306 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/11/10 17:53 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/11/07 12:42 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/11/06 05:50 linux-5.15.y cc5ec8769306 a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/11/04 18:17 linux-5.15.y cc5ec8769306 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/10/30 03:24 linux-5.15.y cc5ec8769306 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/10/29 09:37 linux-5.15.y ac56c046adf4 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in gc_worker
2025/10/16 19:57 linux-5.15.y 29e53a5b1c4f 19568248 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in gc_worker
2025/10/02 20:05 linux-5.15.y 29e53a5b1c4f 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/09/27 11:32 linux-5.15.y 43bb85222e53 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/09/25 09:26 linux-5.15.y 43bb85222e53 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/09/14 13:22 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/09/10 17:26 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/08/30 10:43 linux-5.15.y 01879f56bdde 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in gc_worker
2025/08/30 05:49 linux-5.15.y 01879f56bdde 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in gc_worker
2025/07/25 22:17 linux-5.15.y c79648372d02 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/07/11 09:40 linux-5.15.y 2f693b607545 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/06/29 02:58 linux-5.15.y 3dea0e7f549e fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/06/26 20:26 linux-5.15.y 1c700860e8bc 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/06/09 16:11 linux-5.15.y 1c700860e8bc 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/06/07 22:11 linux-5.15.y 1c700860e8bc 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/06/05 05:57 linux-5.15.y 1c700860e8bc 6b6b5f21 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/06/03 07:26 linux-5.15.y 98f47d0e9b8c a30356b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/05/28 23:18 linux-5.15.y 98f47d0e9b8c 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/05/27 15:00 linux-5.15.y 98f47d0e9b8c 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/05/19 18:23 linux-5.15.y a68c15152131 b84f0537 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/05/14 19:36 linux-5.15.y 3b8db0e4f263 a4fa04ef .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/05/07 15:14 linux-5.15.y 16fdf2c7111b 350f4ffc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/05/06 00:06 linux-5.15.y 16fdf2c7111b 6ca47dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/05/05 20:09 linux-5.15.y 16fdf2c7111b 6ca47dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2024/02/11 11:46 linux-5.15.y 6139f2a02fe0 77b23aa1 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in gc_worker
2025/06/30 11:16 linux-5.15.y 3dea0e7f549e fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: rcu detected stall in gc_worker
* Struck through repros no longer work on HEAD.