rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=2f5/1/0x4000000000000000 softirq=21413/21413 fqs=185 
	(detected by 1, t=10502 jiffies, g=28701, q=691)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4284 Comm: kworker/0:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:deref_stack_regs arch/x86/kernel/unwind_orc.c:375 [inline]
RIP: 0010:unwind_next_frame+0xddc/0x1cf0 arch/x86/kernel/unwind_orc.c:552
Code: 0f b6 04 28 84 c0 4c 8d 73 35 4c 8b 7c 24 08 0f 85 42 0c 00 00 41 c6 06 01 e9 cc 00 00 00 48 81 c7 80 00 00 00 e8 84 16 00 00 <49> 89 c7 48 8b 44 24 10 80 3c 28 00 4c 8d 73 48 74 08 4c 89 f7 e8
RSP: 0018:ffffc900031ef048 EFLAGS: 00000086
RAX: ffffffff8165734f RBX: ffffc900031ef140 RCX: ffffffff8ee00401
RDX: ffffc900031ef998 RSI: ffffffff8ee0041c RDI: ffffc900031efa18
RBP: dffffc0000000000 R08: 0000000000000028 R09: ffffc900031ef190
R10: dffffc0000000000 R11: fffff5200063de34 R12: 1ffffffff1efcde1
R13: 1ffffffff1efcde1 R14: ffffc900031f0000 R15: ffffc900031e8000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000003 CR3: 000000002d881000 CR4: 00000000003506f0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 perf_callchain_kernel+0x470/0x760 arch/x86/events/core.c:2783
 get_perf_callchain+0x356/0x460 kernel/events/callchain.c:200
 perf_callchain kernel/events/core.c:7616 [inline]
 perf_prepare_sample+0x352/0x1cb0 kernel/events/core.c:7643
 __perf_event_output kernel/events/core.c:7812 [inline]
 perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7832
 __perf_event_overflow+0x35f/0x550 kernel/events/core.c:9525
 perf_tp_event+0x324/0xbe0 kernel/events/core.c:10057
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10031
 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
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 82 fc 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900031efa40 EFLAGS: 00000206
RAX: 667e174956d8fb00 RBX: 1ffff9200063df4c RCX: 667e174956d8fb00
RDX: dffffc0000000000 RSI: ffffffff8a2b2b60 RDI: ffffffff8a7a4bc0
RBP: ffffc900031efb18 R08: ffffffff910460ff R09: 1ffffffff2208c1f
R10: dffffc0000000000 R11: fffffbfff2208c20 R12: ffffffff8d123400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 __neigh_notify+0x282/0x2e0 net/core/neighbour.c:3395
 neigh_cleanup_and_release+0x9d/0x250 net/core/neighbour.c:101
 neigh_periodic_work+0x406/0xc70 net/core/neighbour.c:947
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10131 jiffies! g28701 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=19247
rcu: rcu_preempt kthread starved for 10132 jiffies! g28701 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:26864 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
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_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x1110/0x1270 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x845/0x1120 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:queued_write_lock_slowpath+0x129/0x270 kernel/locking/qrwlock.c:78
Code: f0 41 81 0e 00 01 00 00 43 0f b6 04 27 84 c0 74 37 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 2a 4c 89 f7 e8 0b 08 60 00 eb 20 f3 90 <43> 0f b6 04 27 84 c0 74 15 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 08
RSP: 0018:ffffc90000dd04e0 EFLAGS: 00000206
RAX: 00000000000001ff RBX: ffffc90000dd0530 RCX: ffffffff815e601f
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8e36b818
RBP: ffffc90000dd0590 R08: ffffffff8e36b81b R09: 1ffffffff1c6d703
R10: dffffc0000000000 R11: fffffbfff1c6d704 R12: dffffc0000000000
R13: 1ffff920001ba0a0 R14: ffffffff8e36b818 R15: 1ffffffff1c6d703
 queued_write_lock include/asm-generic/qrwlock.h:97 [inline]
 do_raw_write_lock+0x1e6/0x260 kernel/locking/spinlock_debug.c:210
 ___neigh_create+0xdf3/0x2210 net/core/neighbour.c:625
 ip6_finish_output2+0xacc/0x1640 net/ipv6/ip6_output.c:129
 dst_output include/net/dst.h:452 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ndisc_send_skb+0xb7c/0x1410 net/ipv6/ndisc.c:513
 addrconf_rs_timer+0x367/0x640 net/ipv6/addrconf.c:3974
 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:default_idle+0xb/0x10 arch/x86/kernel/process.c:730
Code: b7 48 89 df e8 c6 45 ec f7 eb ad e8 6f a7 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 07 ab 53 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffc90000d67d48 EFLAGS: 000002c2
RAX: 49b4f022159bda00 RBX: ffff88813fe48000 RCX: 49b4f022159bda00
RDX: 0000000000000001 RSI: ffffffff8a2b2b60 RDI: ffffffff8a7a4bc0
RBP: ffffc90000d67e80 R08: ffff8880b8f3b30b R09: 1ffff110171e7661
R10: dffffc0000000000 R11: ffffed10171e7662 R12: 1ffff920001acfb4
R13: dffffc0000000000 R14: 1ffff11027fc9000 R15: 0000000000000000
 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:202 [inline]
 do_idle+0x3a1/0x650 kernel/sched/idle.c:326
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:424
 start_secondary+0x32f/0x430 arch/x86/kernel/smpboot.c:281
 secondary_startup_64_no_verify+0xb1/0xbb
 </TASK>