rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=fb5/1/0x4000000000000000 softirq=5153/5158 fqs=5250 (t=10502 jiffies g=5037 q=186) NMI backtrace for cpu 0 CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.17.0-rc3-syzkaller-00316-gb81b1829e7e3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline] check_cpu_stall kernel/rcu/tree_stall.h:688 [inline] rcu_pending kernel/rcu/tree.c:3919 [inline] rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2617 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:qdisc_pkt_len include/net/sch_generic.h:816 [inline] RIP: 0010:tcf_police_act+0x388/0x11d0 net/sched/act_police.c:264 Code: 03 00 00 e8 1a ab 28 fa 4c 89 fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 4c 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 5b 0b 00 00 48 8d 7d 10 45 8b 6c 24 28 48 b8 00 00 00 RSP: 0018:ffffc90000cc6c68 EFLAGS: 00000206 RAX: 0000000000000003 RBX: ffff88807d7b1400 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff874fcc76 RDI: 0000000000000003 RBP: ffff88801b377200 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff874fcc68 R11: 0000000000000000 R12: ffff88802320ab40 R13: ffff88801b377204 R14: 0000000000000000 R15: ffff88802320ab68 tcf_action_exec net/sched/act_api.c:1049 [inline] tcf_action_exec+0x1a6/0x530 net/sched/act_api.c:1026 tcf_exts_exec include/net/pkt_cls.h:326 [inline] route4_classify+0xef0/0x1400 net/sched/cls_route.c:179 __tcf_classify net/sched/cls_api.c:1549 [inline] tcf_classify+0x3e8/0x9d0 net/sched/cls_api.c:1615 prio_classify net/sched/sch_prio.c:42 [inline] prio_enqueue+0x3a7/0x790 net/sched/sch_prio.c:75 dev_qdisc_enqueue+0x40/0x300 net/core/dev.c:3668 __dev_xmit_skb net/core/dev.c:3756 [inline] __dev_queue_xmit+0x1f61/0x3660 net/core/dev.c:4081 neigh_hh_output include/net/neighbour.h:533 [inline] neigh_output include/net/neighbour.h:547 [inline] ip_finish_output2+0x14dc/0x2170 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288 ip_finish_output+0x32/0x200 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x196/0x310 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:451 [inline] ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:126 iptunnel_xmit+0x628/0xa50 net/ipv4/ip_tunnel_core.c:82 geneve_xmit_skb drivers/net/geneve.c:966 [inline] geneve_xmit+0x10c8/0x3530 drivers/net/geneve.c:1077 __netdev_start_xmit include/linux/netdevice.h:4683 [inline] netdev_start_xmit include/linux/netdevice.h:4697 [inline] xmit_one net/core/dev.c:3473 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3489 __dev_queue_xmit+0x2985/0x3660 net/core/dev.c:4116 neigh_resolve_output net/core/neighbour.c:1528 [inline] neigh_resolve_output+0x50e/0x830 net/core/neighbour.c:1508 neigh_output include/net/neighbour.h:549 [inline] ip6_finish_output2+0x56e/0x14f0 net/ipv6/ip6_output.c:126 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508 ndisc_send_ns+0x3a9/0x840 net/ipv6/ndisc.c:650 addrconf_dad_work+0xc3f/0x1340 net/ipv6/addrconf.c:4153 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 03 00 add (%rax),%eax 2: 00 e8 add %ch,%al 4: 1a ab 28 fa 4c 89 sbb -0x76b305d8(%rbx),%ch a: fa cli b: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 12: fc ff df 15: 48 c1 ea 03 shr $0x3,%rdx 19: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx 1d: 4c 89 f8 mov %r15,%rax 20: 83 e0 07 and $0x7,%eax 23: 83 c0 03 add $0x3,%eax 26: 38 d0 cmp %dl,%al 28: 7c 08 jl 0x32 * 2a: 84 d2 test %dl,%dl <-- trapping instruction 2c: 0f 85 5b 0b 00 00 jne 0xb8d 32: 48 8d 7d 10 lea 0x10(%rbp),%rdi 36: 45 8b 6c 24 28 mov 0x28(%r12),%r13d 3b: 48 rex.W 3c: b8 .byte 0xb8 3d: 00 00 add %al,(%rax)