rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10500 ticks this GP) idle=7a2/1/0x4000000000000004 softirq=9875/9879 fqs=335 
	(t=10500 jiffies g=5505 q=3003)
rcu: rcu_preempt kthread starved for 6977 jiffies! g5505 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=2
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29272    11      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x8e1/0x1f30 kernel/sched/core.c:4081
 schedule+0xdc/0x2b0 kernel/sched/core.c:4155
 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0x9b2/0x18d0 kernel/rcu/tree.c:1821
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 8007 Comm: syz-executor.1 Not tainted 5.4.0-syzkaller #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq.cold+0x509/0xc02 kernel/rcu/tree.c:2271
 update_process_times+0x2d/0x70 kernel/time/timer.c:1726
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1638
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
RIP: 0010:sock_net include/net/sock.h:2469 [inline]
RIP: 0010:netlink_broadcast_filtered+0x5a/0xd20 net/netlink/af_netlink.c:1485
Code: fb 48 8d 7b 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 c3 0b 00 00 4c 8b 7d d0 4c 89 ef 8b 75 b8 <49> 8b 47 30 48 89 45 c0 e8 f9 8b ff ff 48 c7 c7 a0 9f c2 89 48 89
RSP: 0018:ffff88807ec09580 EFLAGS: 00010246 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffff88806fdad000 RCX: 0000000000000003
RDX: 1ffff1100dfb5a06 RSI: 0000000000000a20 RDI: ffff88807b58bac0
RBP: ffff88807ec09620 R08: 0000000000000a20 R09: 0000000000000000
R10: ffffed100e89678a R11: ffff8880744b3c57 R12: 0000000000000003
R13: ffff88807b58bac0 R14: 0000000000000000 R15: ffff88806fdad000
 netlink_broadcast net/netlink/af_netlink.c:1534 [inline]
 nlmsg_multicast include/net/netlink.h:968 [inline]
 nlmsg_notify+0x93/0x250 net/netlink/af_netlink.c:2520
 rtnl_notify+0xc5/0xf0 net/core/rtnetlink.c:737
 __neigh_notify+0xe3/0x160 net/core/neighbour.c:3365
 neigh_cleanup_and_release+0xf6/0x430 net/core/neighbour.c:105
 neigh_del net/core/neighbour.c:197 [inline]
 neigh_remove_one+0x3ba/0x440 net/core/neighbour.c:218
 neigh_forced_gc net/core/neighbour.c:245 [inline]
 neigh_alloc net/core/neighbour.c:392 [inline]
 ___neigh_create+0x1674/0x2560 net/core/neighbour.c:580
 __neigh_create+0x2f/0x40 net/core/neighbour.c:674
 ip6_finish_output2+0x94f/0x25c0 net/ipv6/ip6_output.c:113
 __ip6_finish_output+0x444/0xaa0 net/ipv6/ip6_output.c:142
 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x25e/0x880 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 mld_sendpack+0x9c2/0xed0 net/ipv6/mcast.c:1682
 mld_send_initial_cr.part.0+0x114/0x160 net/ipv6/mcast.c:2099
 mld_send_initial_cr net/ipv6/mcast.c:2083 [inline]
 mld_dad_timer_expire+0x42/0x230 net/ipv6/mcast.c:2118
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers kernel/time/timer.c:1773 [inline]
 __run_timers kernel/time/timer.c:1740 [inline]
 run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x4f/0x80 kernel/locking/spinlock.c:199
Code: c0 68 34 13 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 33 48 83 3d 12 6a 96 01 00 74 20 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 e7 ab d3 f9 65 8b 05 18 54 85 78 85 c0 74 06 41
RSP: 0018:ffff888064e9f8d8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff122668d RBX: ffff888064e94040 RCX: 0000000000000006
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff888064e948d4
RBP: ffff888064e9f8e0 R08: 1ffffffff15377bb R09: fffffbfff15377bc
R10: fffffbfff15377bb R11: ffffffff8a9bbddf R12: ffff88807ec37380
R13: ffff88806638c0c0 R14: 0000000000000000 R15: 0000000000000002
 finish_lock_switch kernel/sched/core.c:3124 [inline]
 finish_task_switch+0x147/0x750 kernel/sched/core.c:3224
 context_switch kernel/sched/core.c:3388 [inline]
 __schedule+0x8e9/0x1f30 kernel/sched/core.c:4081
 preempt_schedule_common+0x4f/0xe0 kernel/sched/core.c:4236
 preempt_schedule+0x4b/0x60 kernel/sched/core.c:4261
 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50
 smp_call_function_single+0x410/0x480 kernel/smp.c:313
 task_function_call+0xe9/0x180 kernel/events/core.c:114
 perf_install_in_context+0x308/0x5a0 kernel/events/core.c:2746
 __do_sys_perf_event_open+0x1cbc/0x2c70 kernel/events/core.c:11543
 __se_sys_perf_event_open kernel/events/core.c:11151 [inline]
 __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:11151
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a759
Code: bd b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 8b b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fbe0eba7c88 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 000000000071bf00 RCX: 000000000045a759
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000000020000180
RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007fbe0eba86d4
R13: 00000000004aec17 R14: 00000000006f1cb0 R15: 00000000ffffffff