INFO: rcu detected stall in hsr_announce (4)

Status: upstream: reported on 2026/08/30 08:37
Reported-by: syzbot+c9e6bb99fa583786304e@syzkaller.appspotmail.com
First crash: 48d, last: 10d
▶ ▼ Similar bugs (20)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in hsr_announce 1 3 673d 774d 0/3 auto-obsoleted due to no activity on 2025/03/22 17:50
upstream INFO: rcu detected stall in hsr_announce (3) net 1 1 2509d 2509d 0/29 closed as invalid on 2019/12/04 14:04
linux-6.1 INFO: rcu detected stall in hsr_announce (2) 1 2 322d 348d 0/3 auto-obsoleted due to no activity on 2026/03/09 02:56
upstream INFO: rcu detected stall in hsr_announce (5) net 1 4 1797d 1809d 0/29 closed as invalid on 2022/02/08 10:00
linux-6.6 BUG: soft lockup in hsr_announce origin:lts-only 1 syz, C error 5 33d 141d 0/2 upstream: reported C repro on 2026/05/28 20:15
upstream INFO: rcu detected stall in hsr_announce (6) kvm 1 2 1635d 1635d 0/29 auto-closed as invalid on 2022/06/25 07:59
linux-4.14 INFO: rcu detected stall in hsr_announce 1 syz, C error 25 2297d 2495d 0/1 upstream: reported C repro on 2019/12/17 23:42
upstream INFO: rcu detected stall in hsr_announce (4) net 1 1 2135d 2135d 0/29 auto-closed as invalid on 2021/03/11 15:56
linux-5.15 INFO: rcu detected stall in hsr_announce (3) 1 5 230d 291d 0/3 auto-obsoleted due to no activity on 2026/06/09 03:32
linux-6.1 INFO: rcu detected stall in hsr_announce (3) 1 3 99d 113d 0/3 upstream: reported on 2026/06/26 13:35
upstream INFO: rcu detected stall in hsr_announce net 1 1 2589d 2589d 0/29 auto-closed as invalid on 2019/11/13 18:24
linux-6.6 INFO: rcu detected stall in hsr_announce 1 1 305d 305d 0/2 auto-obsoleted due to no activity on 2026/03/26 05:20
upstream INFO: rcu detected stall in hsr_announce (2) net 1 3 2514d 2514d 0/29 closed as invalid on 2019/11/29 14:24
upstream INFO: rcu detected stall in hsr_announce (7) net 1 30 613d 613d 0/29 closed as invalid on 2025/03/17 11:18
linux-5.15 INFO: rcu detected stall in hsr_announce (2) 1 1 422d 422d 0/3 auto-obsoleted due to no activity on 2025/11/28 17:51
linux-5.15 INFO: rcu detected stall in hsr_announce 1 6 746d 792d 0/3 auto-obsoleted due to no activity on 2025/01/08 22:52
linux-4.19 INFO: rcu detected stall in hsr_announce 1 1 2209d 2209d 0/1 auto-closed as invalid on 2021/01/27 07:34
linux-4.19 BUG: soft lockup in hsr_announce (2) 1 7 1460d 1914d 0/1 auto-obsoleted due to no activity on 2023/02/15 11:56
upstream BUG: soft lockup in hsr_announce (2) net 1 3 1115d 1124d 0/29 auto-obsoleted due to no activity on 2023/12/27 12:08
upstream BUG: soft lockup in hsr_announce (3) prio:normal net 1 syz 38 111d 542d 0/29 auto-obsoleted due to no activity on 2026/10/05 15:31

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=345/1/0x4000000000000000 softirq=39393/39394 fqs=4532 
	(t=10500 jiffies g=58753 q=1162)
NMI backtrace for cpu 0
CPU: 0 PID: 15992 Comm: syz.5.3243 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x22d/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31f/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ec/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b0/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x397/0x8b0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:tk_clock_read kernel/time/timekeeping.c:195 [inline]
RIP: 0010:timekeeping_get_delta kernel/time/timekeeping.c:255 [inline]
RIP: 0010:timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
RIP: 0010:ktime_get_with_offset+0x165/0x320 kernel/time/timekeeping.c:874
Code: 3d a8 f7 c9 0a 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 ff e8 41 48 55 00 4c 89 ff 41 ff 17 <49> 89 c7 4c 8b 35 89 f7 c9 0a 4c 8b 25 7a f7 c9 0a 4c 8b 2d 6b f7
RSP: 0018:ffffc900000074c8 EFLAGS: 00000206
RAX: 0000013c43772ef0 RBX: 000000000001d0e2 RCX: 0000000000000000
RDX: 0000013c00000000 RSI: 0000000000000000 RDI: ffffffff8c15e8a0
RBP: 000000000001d1a0 R08: ffffffff902141bf R09: 1ffffffff2042837
R10: dffffc0000000000 R11: fffffbfff2042838 R12: 0022d35a531740e0
R13: 000001fb63109b96 R14: ffffffff8c331848 R15: ffffffff8c15e8a0
 ktime_get_real include/linux/timekeeping.h:79 [inline]
 __net_timestamp include/linux/skbuff.h:3982 [inline]
 netif_rx_internal+0x379/0x550 net/core/dev.c:4992
 netif_rx+0x94/0x380 net/core/dev.c:5044
 veth_forward_skb drivers/net/veth.c:297 [inline]
 veth_xmit+0x603/0xa50 drivers/net/veth.c:350
 __netdev_start_xmit include/linux/netdevice.h:5049 [inline]
 netdev_start_xmit include/linux/netdevice.h:5063 [inline]
 xmit_one net/core/dev.c:3662 [inline]
 dev_hard_start_xmit+0x297/0x7d0 net/core/dev.c:3678
 __dev_queue_xmit+0x195d/0x2e50 net/core/dev.c:4305
 hsr_xmit net/hsr/hsr_forward.c:340 [inline]
 hsr_forward_do net/hsr/hsr_forward.c:431 [inline]
 hsr_forward_skb+0xf82/0x16b0 net/hsr/hsr_forward.c:584
 send_hsr_supervision_frame+0x5f7/0xb90 net/hsr/hsr_device.c:348
 hsr_announce+0x168/0x310 net/hsr/hsr_device.c:404
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:finish_lock_switch+0x12f/0x290 kernel/sched/core.c:4804
Code: 83 c7 18 be ff ff ff ff e8 be bc 6d 08 85 c0 74 46 4d 85 ff 75 62 0f 1f 44 00 00 48 89 df e8 18 2d 77 08 e8 a3 f2 2a 00 fb 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 2f 0e fe ff 43 80 3c 2c
RSP: 0018:ffffc9000324f7b8 EFLAGS: 00000282
RAX: b21526fddf865200 RBX: ffff888026471dc0 RCX: b21526fddf865200
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4b80
RBP: 1ffff11017207613 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: 1ffff110172075c1
R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000
 finish_task_switch+0x12f/0x650 kernel/sched/core.c:4921
 context_switch kernel/sched/core.c:5052 [inline]
 __schedule+0x11cb/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 freezable_schedule include/linux/freezer.h:172 [inline]
 futex_wait_queue_me+0x22b/0x440 kernel/futex/core.c:2866
 futex_wait+0x256/0x680 kernel/futex/core.c:2967
 do_futex+0xdc2/0x12b0 kernel/futex/core.c:4018
 __do_sys_futex kernel/futex/core.c:4095 [inline]
 __se_sys_futex+0x389/0x420 kernel/futex/core.c:4076
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fce1ca67199
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fce1acbf0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fce1cceefa8 RCX: 00007fce1ca67199
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fce1cceefa8
RBP: 00007fce1cceefa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fce1ccef038 R14: 00007fff39fdea70 R15: 00007fff39fdeb58
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/06 15:07 linux-5.15.y a051a4bf909f f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in hsr_announce
2026/09/13 05:40 linux-5.15.y 0996e0926f6b 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in hsr_announce
2026/09/02 09:06 linux-5.15.y 28c35638ec51 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in hsr_announce
2026/08/30 08:36 linux-5.15.y 28c35638ec51 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in hsr_announce
* Struck through repros no longer work on HEAD.