======================================
| [   15.449460][    C3] 1 lock held by swapper/3/0:
| [ 15.449638][ C3] #0: ffffc90000290d60 ((&n->timer)){+.-.}-{0:0}, at: call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
| [   15.449973][    C3]
| [   15.449973][    C3] stack backtrace:
[   15.450203][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   15.450205][    C3] Call Trace:
[   15.450206][    C3]  <IRQ>
[ 15.450210][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 15.450219][ C3] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 15.450229][ C3] icmp6_send (./include/net/net_namespace.h:404 ./include/linux/netdevice.h:2669 net/ipv6/icmp.c:476) 
[ 15.450235][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 15.450251][ C3] ? __pfx_icmp6_send (net/ipv6/icmp.c:452) 
[ 15.450259][ C3] ? __pfx_validate_chain (kernel/locking/lockdep.c:3862) 
[ 15.450263][ C3] ? 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) 
[ 15.450267][ C3] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 15.450277][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 15.450284][ C3] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[ 15.450290][ C3] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 15.450294][ C3] ? neigh_invalidate (net/core/neighbour.c:1008) 
[ 15.450299][ C3] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 15.450303][ C3] ? lock_acquire.part.0 (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853) 
[ 15.450314][ C3] ip6_link_failure (./include/linux/skbuff.h:1152 net/ipv6/route.c:2801) 
[ 15.450323][ C3] ndisc_error_report (./include/net/dst.h:429 net/ipv6/ndisc.c:731) 
[ 15.450329][ C3] neigh_invalidate (net/core/neighbour.c:1008) 
[ 15.450338][ C3] neigh_timer_handler (net/core/neighbour.c:1109 (discriminator 2)) 
[ 15.450348][ C3] ? __pfx_neigh_timer_handler (net/core/neighbour.c:1032) 
[ 15.450352][ C3] call_timer_fn (kernel/time/timer.c:1789) 
[ 15.450355][ C3] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 15.450357][ C3] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 15.450362][ C3] ? __pfx_call_timer_fn (kernel/time/timer.c:1766) 
[ 15.450365][ C3] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 15.450383][ C3] __run_timers (kernel/time/timer.c:1841 kernel/time/timer.c:2414) 
[ 15.450390][ C3] ? __pfx_neigh_timer_handler (net/core/neighbour.c:1032) 
[ 15.450401][ C3] ? __pfx___run_timers (kernel/time/timer.c:2385) 
[ 15.450404][ C3] ? clockevents_program_event (kernel/time/clockevents.c:326) 
[ 15.450415][ C3] ? 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) 
[ 15.450420][ C3] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 15.450423][ C3] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 15.450427][ C3] ? run_timer_softirq (kernel/time/timer.c:2426 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 15.450437][ C3] run_timer_softirq (kernel/time/timer.c:2427 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 15.450442][ C3] handle_softirqs (kernel/softirq.c:561) 
[ 15.450454][ C3] __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) 
[ 15.450458][ C3] irq_exit_rcu (kernel/softirq.c:680) 
[ 15.450461][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   15.450465][    C3]  </IRQ>
[   15.450466][    C3]  <TASK>
[ 15.450469][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 15.450474][ C3] RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/kernel/process.c:744) 
[ 15.450477][ C3] 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
[   15.450480][    C3] RSP: 0018:ffffc90000177df8 EFLAGS: 00000242
[   15.450484][    C3] RAX: 0000000000049dad RBX: 1ffff9200002efc1 RCX: ffffffffa7f66b35
[   15.450486][    C3] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa55733d4
[   15.450488][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100da3703a
[   15.450489][    C3] R10: ffff88806d1b81d3 R11: ffff888001bda300 R12: 0000000000000000
[   15.450491][    C3] R13: ffff888001bda300 R14: dffffc0000000000 R15: 0000000000000000
[ 15.450500][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:147) 
[ 15.450505][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 15.450512][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 15.450515][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 15.450518][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 15.450525][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 15.450535][ C3] do_idle (kernel/sched/idle.c:325) 
[ 15.450541][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 15.450545][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 15.450549][ C3] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 
[ 15.450560][ C3] common_startup_64 (arch/x86/kernel/head_64.S:421) 
| [   16.408470][    C2] 1 lock held by swapper/2/0:
| [ 16.408654][ C2] #0: ffffc90000238ae8 ((&n->timer)){+.-.}-{0:0}, at: call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
| [   16.408987][    C2]
| [   16.408987][    C2] stack backtrace:
[   16.409210][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   16.409214][    C2] Call Trace:
[   16.409218][    C2]  <IRQ>
[ 16.409225][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 16.409243][ C2] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 16.409265][ C2] __icmp_send (./include/net/net_namespace.h:404 ./include/linux/netdevice.h:2669 net/ipv4/icmp.c:616) 
[ 16.409283][ C2] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[ 16.409301][ C2] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 16.409309][ C2] ? debug_object_activate (lib/debugobjects.c:837) 
[ 16.409324][ C2] ? __pfx___icmp_send (net/ipv4/icmp.c:596) 
[ 16.409345][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 16.409371][ C2] ? rcu_read_lock_any_held (kernel/rcu/update.c:386 kernel/rcu/update.c:380) 
[ 16.409381][ C2] ? validate_chain (kernel/locking/lockdep.c:3799 kernel/locking/lockdep.c:3819 kernel/locking/lockdep.c:3874) 
[ 16.409412][ C2] ? __pfx_validate_chain (kernel/locking/lockdep.c:3862) 
[ 16.409424][ 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) 
[ 16.409431][ C2] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 16.409457][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 16.409481][ C2] ipv4_send_dest_unreach (net/ipv4/route.c:1241) 
[ 16.409497][ C2] ? neigh_invalidate (net/core/neighbour.c:1008) 
[ 16.409509][ C2] ? __pfx_ipv4_send_dest_unreach (net/ipv4/route.c:1215) 
[ 16.409545][ C2] ipv4_link_failure (./include/linux/skbuff.h:1152 ./include/net/route.h:88 net/ipv4/route.c:1250) 
[ 16.409560][ C2] arp_error_report (./include/net/dst.h:429 net/ipv4/arp.c:296) 
[ 16.409576][ C2] neigh_invalidate (net/core/neighbour.c:1008) 
[ 16.409601][ C2] neigh_timer_handler (net/core/neighbour.c:1109 (discriminator 2)) 
[ 16.409625][ C2] ? __pfx_neigh_timer_handler (net/core/neighbour.c:1032) 
[ 16.409634][ C2] call_timer_fn (kernel/time/timer.c:1789) 
[ 16.409642][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 16.409649][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 16.409660][ C2] ? __pfx_call_timer_fn (kernel/time/timer.c:1766) 
[ 16.409667][ C2] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 16.409715][ C2] __run_timers (kernel/time/timer.c:1841 kernel/time/timer.c:2414) 
[ 16.409725][ C2] ? __pfx_neigh_timer_handler (net/core/neighbour.c:1032) 
[ 16.409752][ C2] ? __pfx___run_timers (kernel/time/timer.c:2385) 
[ 16.409760][ C2] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 16.409780][ 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) 
[ 16.409792][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 16.409801][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 16.409808][ C2] ? timer_expire_remote (kernel/time/timer.c:2426 kernel/time/timer.c:2418 kernel/time/timer.c:2177) 
[ 16.409835][ C2] timer_expire_remote (kernel/time/timer.c:2427 kernel/time/timer.c:2418 kernel/time/timer.c:2177) 
[ 16.409847][ 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) 
[ 16.409865][ C2] ? __pfx_tmigr_handle_remote_cpu (kernel/time/timer_migration.c:905) 
[ 16.409873][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 16.409883][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 16.409934][ C2] tmigr_handle_remote_up (kernel/time/timer_migration.c:1038) 
[ 16.409950][ C2] ? __pfx_tmigr_handle_remote_up (kernel/time/timer_migration.c:1005) 
[ 16.409964][ C2] __walk_groups.isra.0 (kernel/time/timer_migration.c:533) 
[ 16.409985][ C2] tmigr_handle_remote (kernel/time/timer_migration.c:1096) 
[ 16.409996][ C2] ? __pfx_tmigr_handle_remote (kernel/time/timer_migration.c:1059) 
[ 16.410003][ 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) 
[ 16.410015][ C2] ? spin_bug (kernel/locking/spinlock_debug.c:79) 
[ 16.410035][ C2] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4341 kernel/locking/lockdep.c:4408) 
[ 16.410060][ C2] handle_softirqs (kernel/softirq.c:561) 
[ 16.410092][ C2] __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) 
[ 16.410101][ C2] irq_exit_rcu (kernel/softirq.c:680) 
[ 16.410108][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   16.410121][    C2]  </IRQ>
[   16.410123][    C2]  <TASK>
[ 16.410129][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 16.410139][ 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) 
[ 16.410147][ 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
[   16.410153][    C2] RSP: 0018:ffffc90000167df8 EFLAGS: 00000246
[   16.410159][    C2] RAX: 000000000005621b RBX: 1ffff9200002cfc1 RCX: ffffffffa7f66b35
[   16.410164][    C2] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa55733d4
[   16.410168][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100da2703a
[   16.410172][    C2] R10: ffff88806d1381d3 R11: ffff888001bd8040 R12: 0000000000000000
[   16.410176][    C2] R13: ffff888001bd8040 R14: dffffc0000000000 R15: 0000000000000000
[ 16.410201][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:147) 
[ 16.410211][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 16.410229][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 16.410236][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 16.410245][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 16.410262][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 16.410286][ C2] do_idle (kernel/sched/idle.c:325) 
[ 16.410300][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 16.410310][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 16.410321][ 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