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INFO: rcu detected stall in batadv_nc_worker

Status: upstream: reported C repro on 2023/07/06 06:16
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+13306b743f5eee80aab3@syzkaller.appspotmail.com
First crash: 956d, last: 23h37m
Fix commit to backport (bisect log) :
tree: upstream
commit 8c21ab1bae945686c602c5bfa4e3f3352c2452c5
Author: Eric Dumazet <edumazet@google.com>
Date: Tue Aug 29 12:35:41 2023 +0000

  net/sched: fq_pie: avoid stalls in fq_pie_timer()

[report pending]
  
Fix bisection: the issue occurs on the latest tested release (bisect log)
Crash: INFO: rcu detected stall in corrupted (log)
Repro: C syz .config
  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2023/09/18 linux-6.1.y (ToT) 09045dae0d90 C [report] INFO: rcu detected stall in corrupted
2023/09/18 upstream (ToT) 2cf0f7156238 C Didn't crash
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in batadv_nc_worker cgroups mm 1 7 2265d 2267d 0/29 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in batadv_nc_worker (2) mm 1 4 2230d 2231d 0/29 closed as invalid on 2020/01/09 08:13
upstream INFO: rcu detected stall in batadv_nc_worker (3) batman 1 C done inconclusive 585 152d 1963d 0/29 upstream: reported C repro on 2020/10/01 10:35
linux-5.15 INFO: rcu detected stall in batadv_nc_worker origin:lts-only 1 C done 329 16h17m 978d 0/3 upstream: reported C repro on 2023/06/13 20:27
▶ ▼ Fix bisection attempts (2)
Created Duration User Patch Repo Result
2023/11/06 15:29 7h44m fix candidate upstream OK (1) job log
2023/10/25 07:11 2h37m bisect fix linux-6.1.y OK (0) job log log

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2639 jiffies s: 3725 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_preemption_disabled+0x2e/0x110 lib/smp_processor_id.c:55
Code: 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 05 21 b0 d5 75 65 8b 0d c2 05 d6 75 f7 c1 ff ff ff 7f 74 1f <65> 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83
RSP: 0018:ffffc900001e02c8 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 1ffff9200003c068 RCX: 0000000000000101
RDX: 0000000000000100 RSI: ffffffff8adf0c00 RDI: ffffffff8adf0bc0
RBP: ffffc900001e0400 R08: dffffc0000000000 R09: 1ffffffff215e648
R10: dffffc0000000000 R11: fffffbfff215e649 R12: 0000000000000046
R13: dffffc0000000000 R14: 0000000000000101 R15: ffff88813fe70000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00850d000 CR3: 00000000794af000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_unlock_special+0x114/0x510 kernel/rcu/tree_plugin.h:644
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 trace_call_bpf+0x5bb/0x6b0 kernel/trace/bpf_trace.c:137
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:9997
 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 92 30 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900001e0760 EFLAGS: 00000206
RAX: c8ace18a47792f00 RBX: 1ffff9200003c0f4 RCX: c8ace18a47792f00
RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0c20
RBP: ffffc900001e0860 R08: ffffffff90af334f R09: 1ffffffff215e669
R10: dffffc0000000000 R11: fffffbfff215e66a R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 ndisc_send_skb+0xd9d/0x14e0 net/ipv6/ndisc.c:521
 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3979
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x53e/0x800 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:406 [inline]
RIP: 0010:batadv_nc_worker+0xa8/0x600 net/batman-adv/network-coding.c:719
Code: 5e e0 8c f7 85 ed 0f 84 55 02 00 00 45 31 ff 48 89 d8 48 c1 e8 03 48 89 44 24 18 48 89 5c 24 08 4c 89 6c 24 10 48 8b 44 24 18 <42> 80 3c 20 00 74 08 48 89 df e8 b9 c7 dd f7 4a 8d 2c fd 00 00 00
RSP: 0018:ffffc900000e7be0 EFLAGS: 00000293
RAX: 1ffff11005270050 RBX: ffff888029380280 RCX: ffff88813fe70000
RDX: 0000000000000000 RSI: ffffffff8a8c23a0 RDI: ffffffff8adf0c20
RBP: fffffffffffffe38 R08: ffffffff8e1fc32f R09: 1ffffffff1c3f865
R10: dffffc0000000000 R11: fffffbfff1c3f866 R12: dffffc0000000000
R13: ffff888029380290 R14: ffff8880764b0c80 R15: 00000000000001a3
 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (249):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/30 21:55 linux-6.1.y cd9b81672742 ae7dc18c .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in batadv_nc_worker
2025/12/05 14:55 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2023/09/18 20:52 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/25 12:44 linux-6.1.y cd9b81672742 40acda8a .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/03 07:39 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/11/24 08:25 linux-6.1.y f6e38ae624cf 4fb8ef37 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/10/29 04:48 linux-6.1.y 8e6e2188d949 fd2207e7 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/09/15 08:01 linux-6.1.y 3db754f56897 e2beed91 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/04/12 09:53 linux-6.1.y 420102835862 0bd6db41 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/01/26 21:24 linux-6.1.y 75cefdf153f5 9fbd772e .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/01/26 11:00 linux-6.1.y 75cefdf153f5 9fbd772e .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/11 05:37 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: rcu detected stall in batadv_nc_worker
2026/02/15 09:52 linux-6.1.y 8ce36b2849ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/02/14 04:26 linux-6.1.y 8ce36b2849ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/02/13 13:00 linux-6.1.y 8ce36b2849ef 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/02/12 10:32 linux-6.1.y 8ce36b2849ef 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/02/10 14:53 linux-6.1.y 0182cb5b74ee 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/02/10 06:57 linux-6.1.y 0182cb5b74ee 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/02/09 21:43 linux-6.1.y 0182cb5b74ee df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/02/07 03:12 linux-6.1.y 0182cb5b74ee f20fc9f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/02/06 21:35 linux-6.1.y 0182cb5b74ee 97745f52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/02/01 14:26 linux-6.1.y cd9b81672742 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/02/01 11:21 linux-6.1.y cd9b81672742 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/30 20:48 linux-6.1.y cd9b81672742 ae7dc18c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/28 21:54 linux-6.1.y cd9b81672742 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/27 19:43 linux-6.1.y cd9b81672742 9a514c2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/25 15:24 linux-6.1.y cd9b81672742 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/24 07:19 linux-6.1.y cd9b81672742 4f25b9b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/21 10:07 linux-6.1.y cd9b81672742 6f1aa2f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/14 09:00 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/14 02:42 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/10 07:37 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2026/01/06 10:13 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/30 02:50 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/30 00:11 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/29 14:46 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/20 07:08 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/20 02:36 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/18 02:15 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/13 01:08 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/11 18:35 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/06 08:50 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/06 05:42 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/05 09:46 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/03 09:58 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/12/02 12:39 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/11/30 00:08 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/11/26 12:33 linux-6.1.y f6e38ae624cf 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/11/24 21:36 linux-6.1.y f6e38ae624cf bf6fe8fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/11/21 23:56 linux-6.1.y f6e38ae624cf 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/11/20 21:46 linux-6.1.y f6e38ae624cf 2cc4c24a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/11/04 21:58 linux-6.1.y f6e38ae624cf 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/10/29 22:31 linux-6.1.y f6e38ae624cf fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/10/27 22:03 linux-6.1.y 8e6e2188d949 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/10/26 18:40 linux-6.1.y 8e6e2188d949 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/10/23 02:25 linux-6.1.y 8e6e2188d949 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/10/21 17:24 linux-6.1.y 8e6e2188d949 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/10/20 11:56 linux-6.1.y 8e6e2188d949 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/10/19 02:53 linux-6.1.y c2fda4b3f577 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/10/18 08:26 linux-6.1.y c2fda4b3f577 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2025/10/07 09:52 linux-6.1.y 882efbdd9d34 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
2023/07/06 06:15 linux-6.1.y 0f4ac6b4c5f0 ba5dba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in batadv_nc_worker
* Struck through repros no longer work on HEAD.