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: 8h02m, last: 8h02m
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 625d 726d 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 2461d 2461d 0/29 closed as invalid on 2019/12/04 14:04
linux-6.1 INFO: rcu detected stall in hsr_announce (2) 1 2 274d 300d 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 1749d 1761d 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 4 2d00h 93d 0/2 upstream: reported C repro on 2026/05/28 20:15
upstream INFO: rcu detected stall in hsr_announce (6) kvm 1 2 1587d 1587d 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 2249d 2447d 0/1 upstream: reported C repro on 2019/12/17 23:42
upstream INFO: rcu detected stall in hsr_announce (4) net 1 1 2088d 2088d 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 182d 243d 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 51d 65d 0/3 upstream: reported on 2026/06/26 13:35
upstream INFO: rcu detected stall in hsr_announce net 1 1 2541d 2541d 0/29 auto-closed as invalid on 2019/11/13 18:24
linux-6.6 INFO: rcu detected stall in hsr_announce 1 1 257d 257d 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 2466d 2466d 0/29 closed as invalid on 2019/11/29 14:24
upstream INFO: rcu detected stall in hsr_announce (7) net 1 30 565d 565d 0/29 closed as invalid on 2025/03/17 11:18
linux-5.15 INFO: rcu detected stall in hsr_announce (2) 1 1 374d 374d 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 698d 744d 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 2161d 2161d 0/1 auto-closed as invalid on 2021/01/27 07:34
linux-4.19 BUG: soft lockup in hsr_announce (2) 1 7 1412d 1866d 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 1067d 1076d 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 64d 494d 0/29 upstream: reported syz repro on 2025/04/23 07:51

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10501 ticks this GP) idle=989/1/0x4000000000000000 softirq=28372/28372 fqs=5217 
	(t=10502 jiffies g=37857 q=2367)
NMI backtrace for cpu 0
CPU: 0 PID: 10400 Comm: syz.1.1227 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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:rmqueue_pcplist mm/page_alloc.c:3711 [inline]
RIP: 0010:rmqueue mm/page_alloc.c:3742 [inline]
RIP: 0010:get_page_from_freelist+0x1f20/0x2670 mm/page_alloc.c:4189
Code: 8f 84 24 c0 01 00 00 f7 84 24 c0 01 00 00 00 02 00 00 c6 44 08 04 f8 0f 85 89 02 00 00 41 f7 c5 00 02 00 00 74 01 fb 4d 85 f6 <44> 8b 6c 24 2c 0f 84 d5 00 00 00 4c 89 f0 48 c1 e8 03 80 3c 08 00
RSP: 0018:ffffc90000007460 EFLAGS: 00000282
RAX: 1ffff92000000ec0 RBX: ffffffff8be3d820 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a43c0
RBP: ffffc900000076b0 R08: ffffffff901ef1bf R09: 1ffffffff203de37
R10: dffffc0000000000 R11: fffffbfff203de38 R12: ffff88813fffd310
R13: 0000000000000202 R14: ffffea00018bb840 R15: 0000000000112a20
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0xf0/0x280 mm/slub.c:3238
 skb_clone+0x1bd/0x350 net/core/skbuff.c:1523
 hsr_forward_do net/hsr/hsr_forward.c:-1 [inline]
 hsr_forward_skb+0xc02/0x16b0 net/hsr/hsr_forward.c:584
 send_hsr_supervision_frame+0x5f7/0xb90 net/hsr/hsr_device.c:349
 hsr_announce+0x168/0x310 net/hsr/hsr_device.c:405
 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 0e fb 6b 08 85 c0 74 46 4d 85 ff 75 62 0f 1f 44 00 00 48 89 df e8 c8 6a 75 08 e8 33 dd 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:ffffc9000302f7b8 EFLAGS: 00000282
RAX: db5542cd55ed6c00 RBX: ffff88813fe23b80 RCX: db5542cd55ed6c00
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a43c0
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: 0033:0x7f693f00e159
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:00007f693d2660e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f693f295fa8 RCX: 00007f693f00e159
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f693f295fa8
RBP: 00007f693f295fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f693f296038 R14: 00007fff9f4ee1e0 R15: 00007fff9f4ee2c8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.