======================================
| [ 34.554372][ C3] #4: ffff8880102ab358 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_port_query_expired (./include/trace/events/../../../net/bridge/br_private.h:1293 ./include/trace/events/../../../net/bridge/br_private.h:1302 net/bridge/br_multicast.c:1906) bridge 
| [ 34.554831][ C3] #5: ffffffffb915b5c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit (./include/linux/bottom_half.h:20 ./include/linux/rcupdate.h:901 net/core/dev.c:4555) 
| [   34.555377][    C3]
| [   34.555377][    C3] stack backtrace:
[   34.555627][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   34.555630][    C3] Workqueue: events_unbound linkwatch_event
[   34.555636][    C3] Call Trace:
[   34.555638][    C3]  <IRQ>
[ 34.555642][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 34.555652][ C3] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 34.555664][ C3] dev_hard_start_xmit (./include/net/net_namespace.h:418 ./include/linux/netdevice.h:2695 net/core/dev.c:2466 net/core/dev.c:3772 net/core/dev.c:3793) 
[ 34.555676][ C3] __dev_queue_xmit (net/core/dev.h:340 net/core/dev.c:4631) 
[ 34.555686][ C3] ? __build_skb_around (./arch/x86/include/asm/atomic.h:28 ./include/linux/atomic/atomic-arch-fallback.h:503 ./include/linux/atomic/atomic-instrumented.h:68 net/core/skbuff.c:381 net/core/skbuff.c:439) 
[ 34.555698][ C3] ? __pfx___dev_queue_xmit (net/core/dev.c:4538) 
[ 34.555701][ C3] ? __pfx___alloc_skb (net/core/skbuff.c:642) 
[ 34.555707][ C3] ? stack_trace_save (kernel/stacktrace.c:114) 
[ 34.555714][ C3] ? __pfx_stack_trace_save (kernel/stacktrace.c:114) 
[ 34.555722][ C3] ? __pfx___br_multicast_query_handle_vlan (net/bridge/br_multicast.c:909) bridge 
[ 34.555774][ C3] br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 34.555807][ C3] ? __pfx_br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 34.555840][ C3] ? br_multicast_count (./arch/x86/include/asm/bitops.h:206 ./arch/x86/include/asm/bitops.h:238 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 ./include/trace/events/../../../net/bridge/br_private.h:764 net/bridge/br_multicast.c:5052) bridge 
[ 34.555880][ C3] __br_multicast_send_query (net/bridge/br_multicast.c:1813) bridge 
[ 34.555926][ C3] ? __pfx___br_multicast_send_query (net/bridge/br_multicast.c:1789) bridge 
[ 34.555966][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 34.555977][ C3] ? br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 34.556012][ C3] br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 34.556050][ C3] ? __pfx_br_multicast_send_query (net/bridge/br_multicast.c:1852) bridge 
[ 34.556083][ C3] ? br_multicast_port_query_expired (./include/trace/events/../../../net/bridge/br_private.h:1293 ./include/trace/events/../../../net/bridge/br_private.h:1302 net/bridge/br_multicast.c:1906) bridge 
[ 34.556120][ C3] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 34.556156][ C3] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 34.556162][ 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) 
[ 34.556167][ C3] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 34.556171][ C3] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 34.556174][ C3] ? br_multicast_port_query_expired (./include/trace/events/../../../net/bridge/br_private.h:1293 ./include/trace/events/../../../net/bridge/br_private.h:1302 net/bridge/br_multicast.c:1906) bridge 
[ 34.556215][ C3] ? br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 34.556248][ C3] br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 34.556284][ C3] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 34.556318][ C3] call_timer_fn (kernel/time/timer.c:1789) 
[ 34.556322][ C3] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 34.556325][ C3] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 34.556329][ C3] ? __pfx_call_timer_fn (kernel/time/timer.c:1766) 
[ 34.556333][ 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) 
[ 34.556342][ C3] ? mark_held_locks (kernel/locking/lockdep.c:4323) 
[ 34.556354][ C3] __run_timers (kernel/time/timer.c:1841 kernel/time/timer.c:2414) 
[ 34.556358][ C3] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 34.556400][ C3] ? __pfx___run_timers (kernel/time/timer.c:2385) 
[ 34.556403][ C3] ? clockevents_program_event (kernel/time/clockevents.c:326) 
[ 34.556413][ 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) 
[ 34.556417][ C3] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 34.556421][ C3] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 34.556424][ C3] ? run_timer_softirq (kernel/time/timer.c:2426 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 34.556435][ C3] run_timer_softirq (kernel/time/timer.c:2427 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 34.556440][ C3] handle_softirqs (kernel/softirq.c:561) 
[ 34.556454][ C3] __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) 
[ 34.556458][ C3] irq_exit_rcu (kernel/softirq.c:680) 
[ 34.556460][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   34.556466][    C3]  </IRQ>
[   34.556467][    C3]  <TASK>
[ 34.556469][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 34.556475][ C3] RIP: 0010:addrconf_init_auto_addrs (net/ipv6/addrconf.c:3548) 
[ 34.556480][ C3] Code: 0f ff ff ff e8 81 39 1d fe e9 a5 fe ff ff e8 47 39 1d fe e9 48 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 fd 48 81 c7
All code
========
   0:	0f ff ff             	ud0    %edi,%edi
   3:	ff                   	(bad)
   4:	e8 81 39 1d fe       	call   0xfffffffffe1d398a
   9:	e9 a5 fe ff ff       	jmp    0xfffffffffffffeb3
   e:	e8 47 39 1d fe       	call   0xfffffffffe1d395a
  13:	e9 48 ff ff ff       	jmp    0xffffffffffffff60
  18:	66 90                	xchg   %ax,%ax
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	90                   	nop
  1f:	90                   	nop
  20:	90                   	nop
  21:	90                   	nop
  22:	90                   	nop
  23:	90                   	nop
  24:	90                   	nop
  25:	90                   	nop
  26:	90                   	nop
  27:	90                   	nop
  28:	90                   	nop
  29:	90                   	nop
  2a:*	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)		<-- trapping instruction
  2f:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  36:	fc ff df 
  39:	55                   	push   %rbp
  3a:	48 89 fd             	mov    %rdi,%rbp
  3d:	48                   	rex.W
  3e:	81                   	.byte 0x81
  3f:	c7                   	.byte 0xc7

Code starting with the faulting instruction
===========================================
   0:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   5:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   c:	fc ff df 
   f:	55                   	push   %rbp
  10:	48 89 fd             	mov    %rdi,%rbp
  13:	48                   	rex.W
  14:	81                   	.byte 0x81
  15:	c7                   	.byte 0xc7
[   34.556483][    C3] RSP: 0018:ffffc900002dfa70 EFLAGS: 00000286
[   34.556486][    C3] RAX: 0000000080000000 RBX: ffff88800adb2010 RCX: ffff88800adb2610
[   34.556488][    C3] RDX: 0000000000000000 RSI: ffffffffb99f0a08 RDI: ffff8880084c9000
[   34.556490][    C3] RBP: ffff8880084c9000 R08: 0000000000000000 R09: fffffbfff7372c32
[   34.556492][    C3] R10: ffffffffb9b96197 R11: ffffed100130b4ac R12: ffffc900002dfb30
[   34.556494][    C3] R13: ffff8880085e0800 R14: ffff88800adb2000 R15: ffffffffbbb3c5c0
[ 34.556512][ C3] addrconf_notify (./include/linux/err.h:81 net/ipv6/addrconf.c:3741) 
[ 34.556521][ C3] notifier_call_chain (kernel/notifier.c:85 (discriminator 2)) 
[ 34.556535][ C3] netdev_state_change (net/core/dev.c:1538 net/core/dev.c:1529) 
[ 34.556539][ C3] ? __pfx_netdev_state_change (net/core/dev.c:1530) 
[ 34.556555][ C3] linkwatch_do_dev (net/core/link_watch.c:186) 
[ 34.556559][ C3] __linkwatch_run_queue (./include/linux/spinlock.h:376 net/core/link_watch.c:245) 
[ 34.556567][ C3] ? __pfx___linkwatch_run_queue (net/core/link_watch.c:195) 
[ 34.556574][ C3] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 34.556584][ C3] linkwatch_event (net/core/link_watch.c:287) 
[ 34.556586][ C3] process_one_work (kernel/workqueue.c:3238) 
[ 34.556600][ C3] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 34.556606][ C3] ? __pfx_process_one_work (kernel/workqueue.c:3140) 
[ 34.556619][ C3] ? assign_work (kernel/workqueue.c:1200) 
[ 34.556630][ C3] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400) 
[ 34.556644][ C3] ? __pfx_worker_thread (kernel/workqueue.c:3346) 
[ 34.556651][ C3] kthread (kernel/kthread.c:464) 
[ 34.556655][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 34.556664][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 34.556670][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 34.556676][ C3] ? __pfx_kthread (kernel/kthread.c:413) 


Finger prints:
lockdep_rcu_suspicious:dev_hard_start_xmit:__dev_queue_xmit:br_dev_queue_push_xmit:__br_multicast_send_query