======================================
| [   15.938526][    C2] 1 lock held by swapper/2/0:
| [ 15.938714][ C2] #0: ffffc90000238ae8 ((&n->timer)){+.-.}-{0:0}, at: call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
| [   15.939039][    C2]
| [   15.939039][    C2] stack backtrace:
[   15.939266][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   15.939269][    C2] Call Trace:
[   15.939272][    C2]  <IRQ>
[ 15.939280][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 15.939295][ C2] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 15.939316][ C2] icmp6_send (./include/net/net_namespace.h:404 ./include/linux/netdevice.h:2669 net/ipv6/icmp.c:476) 
[ 15.939323][ C2] ? rcu_read_lock_any_held (kernel/rcu/update.c:386 kernel/rcu/update.c:380) 
[ 15.939332][ C2] ? find_stack (lib/stackdepot.c:552 (discriminator 1)) 
[ 15.939372][ C2] ? __pfx_icmp6_send (net/ipv6/icmp.c:452) 
[ 15.939392][ C2] ? __pfx_validate_chain (kernel/locking/lockdep.c:3862) 
[ 15.939403][ C2] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:230) 
[ 15.939411][ C2] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 15.939418][ C2] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 15.939444][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 15.939461][ C2] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[ 15.939478][ C2] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 15.939486][ C2] ? neigh_invalidate (net/core/neighbour.c:1008) 
[ 15.939497][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 15.939506][ C2] ? lock_acquire.part.0 (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853) 
[ 15.939536][ C2] ip6_link_failure (./include/linux/skbuff.h:1152 net/ipv6/route.c:2801) 
[ 15.939555][ C2] ndisc_error_report (./include/net/dst.h:429 net/ipv6/ndisc.c:731) 
[ 15.939569][ C2] neigh_invalidate (net/core/neighbour.c:1008) 
[ 15.939593][ C2] neigh_timer_handler (net/core/neighbour.c:1109 (discriminator 2)) 
[ 15.939618][ C2] ? __pfx_neigh_timer_handler (net/core/neighbour.c:1032) 
[ 15.939627][ C2] call_timer_fn (kernel/time/timer.c:1789) 
[ 15.939634][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 15.939641][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 15.939652][ C2] ? __pfx_call_timer_fn (kernel/time/timer.c:1766) 
[ 15.939660][ C2] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 15.939708][ C2] __run_timers (kernel/time/timer.c:1841 kernel/time/timer.c:2414) 
[ 15.939717][ C2] ? __pfx_neigh_timer_handler (net/core/neighbour.c:1032) 
[ 15.939745][ C2] ? __pfx___run_timers (kernel/time/timer.c:2385) 
[ 15.939752][ C2] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 15.939773][ C2] ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:107 ./include/linux/atomic/atomic-arch-fallback.h:2170 ./include/linux/atomic/atomic-instrumented.h:1302 ./include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:116) 
[ 15.939784][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 15.939794][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 15.939801][ C2] ? timer_expire_remote (kernel/time/timer.c:2426 kernel/time/timer.c:2418 kernel/time/timer.c:2177) 
[ 15.939828][ C2] timer_expire_remote (kernel/time/timer.c:2427 kernel/time/timer.c:2418 kernel/time/timer.c:2177) 
[ 15.939840][ C2] tmigr_handle_remote_cpu (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:87 ./arch/x86/include/asm/irqflags.h:147 kernel/time/timer_migration.c:961) 
[ 15.939856][ C2] ? __pfx_tmigr_handle_remote_cpu (kernel/time/timer_migration.c:905) 
[ 15.939864][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 15.939874][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 15.939925][ C2] tmigr_handle_remote_up (kernel/time/timer_migration.c:1038) 
[ 15.939941][ C2] ? __pfx_tmigr_handle_remote_up (kernel/time/timer_migration.c:1005) 
[ 15.939955][ C2] __walk_groups.isra.0 (kernel/time/timer_migration.c:533) 
[ 15.939976][ C2] tmigr_handle_remote (kernel/time/timer_migration.c:1096) 
[ 15.939987][ C2] ? __pfx_tmigr_handle_remote (kernel/time/timer_migration.c:1059) 
[ 15.939994][ C2] ? kvm_clock_get_cycles (./arch/x86/include/asm/preempt.h:94 arch/x86/kernel/kvmclock.c:80 arch/x86/kernel/kvmclock.c:86) 
[ 15.940001][ C2] ? ktime_get (kernel/time/timekeeping.c:226 (discriminator 4) kernel/time/timekeeping.c:335 (discriminator 4) kernel/time/timekeeping.c:752 (discriminator 4)) 
[ 15.940019][ C2] ? clockevents_program_event (kernel/time/clockevents.c:334 (discriminator 3)) 
[ 15.940054][ C2] handle_softirqs (kernel/softirq.c:561) 
[ 15.940084][ C2] __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) 
[ 15.940092][ C2] irq_exit_rcu (kernel/softirq.c:680) 
[ 15.940099][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   15.940109][    C2]  </IRQ>
[   15.940112][    C2]  <TASK>
[ 15.940118][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 15.940127][ C2] RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/kernel/process.c:744) 
[ 15.940134][ C2] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 03 ac 0f 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
All code
========
   0:	4c 01 c7             	add    %r8,%rdi
   3:	4c 29 c2             	sub    %r8,%rdx
   6:	e9 72 ff ff ff       	jmp    0xffffffffffffff7d
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	f3 0f 1e fa          	endbr64
  1f:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d 03 ac 0f 00 	verw   0xfac03(%rip)        # 0xfac2b
  28:	fb                   	sti
  29:	f4                   	hlt
  2a:*	fa                   	cli		<-- trapping instruction
  2b:	c3                   	ret
  2c:	cc                   	int3
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	cc                   	int3
  30:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
  37:	00 00 00 00 
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop

Code starting with the faulting instruction
===========================================
   0:	fa                   	cli
   1:	c3                   	ret
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	cc                   	int3
   6:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
   d:	00 00 00 00 
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
[   15.940140][    C2] RSP: 0018:ffffc90000167df8 EFLAGS: 00000242
[   15.940146][    C2] RAX: 00000000000544d9 RBX: 1ffff9200002cfc1 RCX: ffffffffb7f66b35
[   15.940150][    C2] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffb55733d4
[   15.940154][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100da2703a
[   15.940158][    C2] R10: ffff88806d1381d3 R11: ffff888001bd8040 R12: 0000000000000000
[   15.940163][    C2] R13: ffff888001bd8040 R14: dffffc0000000000 R15: 0000000000000000
[ 15.940188][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:147) 
[ 15.940198][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 15.940215][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 15.940222][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 15.940231][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 15.940248][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 15.940270][ C2] do_idle (kernel/sched/idle.c:325) 
[ 15.940285][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 15.940294][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 15.940305][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 
[ 15.940333][ C2] common_startup_64 (arch/x86/kernel/head_64.S:421) 
| [   16.067009][    C2] 1 lock held by swapper/2/0:
| [ 16.067189][ C2] #0: ffffc90000238d60 ((&n->timer)){+.-.}-{0:0}, at: call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
| [   16.067505][    C2]
| [   16.067505][    C2] stack backtrace:
[   16.067732][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   16.067736][    C2] Call Trace:
[   16.067739][    C2]  <IRQ>
[ 16.067745][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 16.067760][ C2] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 16.067782][ C2] __icmp_send (./include/net/net_namespace.h:404 ./include/linux/netdevice.h:2669 net/ipv4/icmp.c:616) 
[ 16.067801][ C2] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 16.067808][ C2] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 16.067833][ C2] ? __pfx___icmp_send (net/ipv4/icmp.c:596) 
[ 16.067841][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 16.067854][ C2] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4405) 
[ 16.067886][ C2] ? rcu_read_lock_any_held (kernel/rcu/update.c:386 kernel/rcu/update.c:380) 
[ 16.067895][ C2] ? validate_chain (kernel/locking/lockdep.c:3799 kernel/locking/lockdep.c:3819 kernel/locking/lockdep.c:3874) 
[ 16.067927][ C2] ? __pfx_validate_chain (kernel/locking/lockdep.c:3862) 
[ 16.067938][ C2] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:230) 
[ 16.067945][ C2] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 16.067971][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 16.067995][ C2] ipv4_send_dest_unreach (net/ipv4/route.c:1241) 
[ 16.068010][ C2] ? neigh_invalidate (net/core/neighbour.c:1008) 
[ 16.068021][ C2] ? __pfx_ipv4_send_dest_unreach (net/ipv4/route.c:1215) 
[ 16.068057][ C2] ipv4_link_failure (./include/linux/skbuff.h:1152 ./include/net/route.h:88 net/ipv4/route.c:1250) 
[ 16.068072][ C2] arp_error_report (./include/net/dst.h:429 net/ipv4/arp.c:296) 
[ 16.068087][ C2] neigh_invalidate (net/core/neighbour.c:1008) 
[ 16.068112][ C2] neigh_timer_handler (net/core/neighbour.c:1109 (discriminator 2)) 
[ 16.068136][ C2] ? __pfx_neigh_timer_handler (net/core/neighbour.c:1032) 
[ 16.068145][ C2] call_timer_fn (kernel/time/timer.c:1789) 
[ 16.068152][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 16.068159][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 16.068170][ C2] ? __pfx_call_timer_fn (kernel/time/timer.c:1766) 
[ 16.068192][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 16.068225][ C2] __run_timers (kernel/time/timer.c:1841 kernel/time/timer.c:2414) 
[ 16.068234][ C2] ? __pfx_neigh_timer_handler (net/core/neighbour.c:1032) 
[ 16.068262][ C2] ? __pfx___run_timers (kernel/time/timer.c:2385) 
[ 16.068269][ C2] ? clockevents_program_event (kernel/time/clockevents.c:326) 
[ 16.068291][ C2] ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:107 ./include/linux/atomic/atomic-arch-fallback.h:2170 ./include/linux/atomic/atomic-instrumented.h:1302 ./include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:116) 
[ 16.068302][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 16.068312][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 16.068319][ C2] ? run_timer_softirq (kernel/time/timer.c:2426 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 16.068345][ C2] run_timer_softirq (kernel/time/timer.c:2427 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 16.068359][ C2] handle_softirqs (kernel/softirq.c:561) 
[ 16.068389][ C2] __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) 
[ 16.068398][ C2] irq_exit_rcu (kernel/softirq.c:680) 
[ 16.068404][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   16.068415][    C2]  </IRQ>
[   16.068417][    C2]  <TASK>
[ 16.068423][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 16.068432][ C2] RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/kernel/process.c:744) 
[ 16.068440][ C2] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 03 ac 0f 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
All code
========
   0:	4c 01 c7             	add    %r8,%rdi
   3:	4c 29 c2             	sub    %r8,%rdx
   6:	e9 72 ff ff ff       	jmp    0xffffffffffffff7d
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	f3 0f 1e fa          	endbr64
  1f:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d 03 ac 0f 00 	verw   0xfac03(%rip)        # 0xfac2b
  28:	fb                   	sti
  29:	f4                   	hlt
  2a:*	fa                   	cli		<-- trapping instruction
  2b:	c3                   	ret
  2c:	cc                   	int3
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	cc                   	int3
  30:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
  37:	00 00 00 00 
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop

Code starting with the faulting instruction
===========================================
   0:	fa                   	cli
   1:	c3                   	ret
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	cc                   	int3
   6:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
   d:	00 00 00 00 
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
[   16.068446][    C2] RSP: 0018:ffffc90000167df8 EFLAGS: 00000246
[   16.068452][    C2] RAX: 000000000005540f RBX: 1ffff9200002cfc1 RCX: ffffffffb7f66b35
[   16.068457][    C2] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffb55733d4
[   16.068461][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100da2703a
[   16.068465][    C2] R10: ffff88806d1381d3 R11: ffff888001bd8040 R12: 0000000000000000
[   16.068469][    C2] R13: ffff888001bd8040 R14: dffffc0000000000 R15: 0000000000000000
[ 16.068494][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:147) 
[ 16.068505][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 16.068522][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 16.068529][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 16.068538][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 16.068555][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 16.068577][ C2] do_idle (kernel/sched/idle.c:325) 
[ 16.068592][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 16.068601][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 16.068612][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 


Finger prints:
lockdep_rcu_suspicious:__icmp_send:ipv4_send_dest_unreach:ipv4_link_failure:arp_error_report
lockdep_rcu_suspicious:icmp6_send:ip6_link_failure:ndisc_error_report:neigh_invalidate