rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=6541, q=133)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294953950-4294943447), jiffies_till_next_fqs=1, root ->qsmask 0x0
kworker/1:0     R  running task    27040    17      2 0x80004008
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 <IRQ>
 sched_show_task+0x40f/0x560 kernel/sched/core.c:5954
 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:538 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq+0x1861/0x1ad0 kernel/rcu/tree.c:2271
 update_process_times+0x12d/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:free_thread_stack+0x15e/0x590 kernel/fork.c:280
Code: 08 4c 89 e7 e8 73 94 6a 00 49 8b 1c 24 48 83 c3 08 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 55 94 6a 00 48 8b 3b <be> fc ff ff ff e8 28 04 00 00 43 80 3c 2e 00 74 08 4c 89 e7 e8 39
RSP: 0018:ffffc90000d8f6a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff11012ce42d1 RBX: ffff888096721688 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea00028a7780
RBP: ffffc90000d8f6e0 R08: 000000000003a728 R09: ffffed10121f7709
R10: ffffed10121f7709 R11: 0000000000000000 R12: ffff888096721720
R13: dffffc0000000000 R14: 1ffff11012ce42e4 R15: ffff888090fbb838
 release_task_stack kernel/fork.c:440 [inline]
 put_task_stack+0xa3/0x130 kernel/fork.c:451
 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256
 context_switch kernel/sched/core.c:3388 [inline]
 __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081
 preempt_schedule_common kernel/sched/core.c:4236 [inline]
 preempt_schedule+0xdb/0x120 kernel/sched/core.c:4261
 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50
 __local_bh_enable_ip+0x17d/0x240 kernel/softirq.c:196
 local_bh_enable+0x1f/0x30 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:706 [inline]
 ip6_finish_output2+0x109f/0x13b0 net/ipv6/ip6_output.c:117
 __ip6_finish_output+0x693/0x8c0 net/ipv6/ip6_output.c:142
 ip6_finish_output+0x52/0x1e0 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x2c2/0x3c0 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ndisc_send_skb+0xa35/0xe20 net/ipv6/ndisc.c:505
 ndisc_send_ns+0x5ce/0x7b0 net/ipv6/ndisc.c:647
 addrconf_dad_work+0xabd/0x1c30 net/ipv6/addrconf.c:4120
 process_one_work+0x7ef/0x10d0 kernel/workqueue.c:2264
 worker_thread+0xc01/0x1630 kernel/workqueue.c:2410
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
rcu: rcu_preempt kthread starved for 10531 jiffies! g6541 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29032    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081
 schedule+0x181/0x210 kernel/sched/core.c:4155
 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352