======================================
| [ 258.428395][ C2] #3: ffff888002a53358 (&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 
| [ 258.428870][ C2] #4: ffffffffb035b5c0 (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) 
| [  258.429217][    C2]
| [  258.429217][    C2] stack backtrace:
[  258.429477][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  258.429480][    C2] Workqueue: events_unbound linkwatch_event
[  258.429487][    C2] Call Trace:
[  258.429490][    C2]  <IRQ>
[ 258.429493][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 258.429502][ C2] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 258.429513][ C2] 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) 
[ 258.429525][ C2] __dev_queue_xmit (net/core/dev.h:340 net/core/dev.c:4631) 
[ 258.429536][ C2] ? __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) 
[ 258.429547][ C2] ? __pfx___dev_queue_xmit (net/core/dev.c:4538) 
[ 258.429550][ C2] ? __pfx___alloc_skb (net/core/skbuff.c:642) 
[ 258.429554][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 258.429564][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 258.429571][ C2] ? __pfx___br_multicast_query_handle_vlan (net/bridge/br_multicast.c:909) bridge 
[ 258.429624][ C2] br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 258.429654][ C2] ? hlock_class (kernel/locking/lockdep.c:225) 
[ 258.429659][ C2] ? __pfx_br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 258.429691][ C2] ? 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 
[ 258.429731][ C2] __br_multicast_send_query (net/bridge/br_multicast.c:1813) bridge 
[ 258.429776][ C2] ? __pfx___br_multicast_send_query (net/bridge/br_multicast.c:1789) bridge 
[ 258.429817][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 258.429827][ C2] ? br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 258.429862][ C2] br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 258.429900][ C2] ? __pfx_br_multicast_send_query (net/bridge/br_multicast.c:1852) bridge 
[ 258.429934][ C2] ? 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 
[ 258.429972][ C2] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 258.430006][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 258.430013][ 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) 
[ 258.430017][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 258.430021][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 258.430024][ C2] ? 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 
[ 258.430064][ C2] ? br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 258.430098][ C2] br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 258.430134][ C2] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 258.430168][ C2] call_timer_fn (kernel/time/timer.c:1789) 
[ 258.430172][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 258.430174][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 258.430179][ C2] ? __pfx_call_timer_fn (kernel/time/timer.c:1766) 
[ 258.430182][ 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) 
[ 258.430191][ C2] ? mark_held_locks (kernel/locking/lockdep.c:4323) 
[ 258.430203][ C2] __run_timers (kernel/time/timer.c:1841 kernel/time/timer.c:2414) 
[ 258.430207][ C2] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 258.430249][ C2] ? __pfx___run_timers (kernel/time/timer.c:2385) 
[ 258.430252][ C2] ? clockevents_program_event (kernel/time/clockevents.c:326) 
[ 258.430262][ 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) 
[ 258.430267][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 258.430270][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 258.430273][ C2] ? run_timer_softirq (kernel/time/timer.c:2426 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 258.430284][ C2] run_timer_softirq (kernel/time/timer.c:2427 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 258.430289][ C2] handle_softirqs (kernel/softirq.c:561) 
[ 258.430297][ C2] ? do_raw_spin_unlock (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141) 
[ 258.430305][ C2] __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) 
[ 258.430308][ C2] irq_exit_rcu (kernel/softirq.c:680) 
[ 258.430311][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[  258.430316][    C2]  </IRQ>
[  258.430317][    C2]  <TASK>
[ 258.430320][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 258.430325][ C2] RIP: 0010:lock_is_held_type (kernel/locking/lockdep.c:5928) 
[ 258.430328][ C2] Code: 94 c5 b8 ff ff ff ff 65 0f c1 05 e1 d9 cf 50 83 f8 01 75 2d 9c 58 f6 c4 02 75 37 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 45 31 ed eb
All code
========
   0:	94                   	xchg   %eax,%esp
   1:	c5 b8 ff             	(bad)
   4:	ff                   	(bad)
   5:	ff                   	(bad)
   6:	ff 65 0f             	jmp    *0xf(%rbp)
   9:	c1 05 e1 d9 cf 50 83 	roll   $0x83,0x50cfd9e1(%rip)        # 0x50cfd9f1
  10:	f8                   	clc
  11:	01 75 2d             	add    %esi,0x2d(%rbp)
  14:	9c                   	pushf
  15:	58                   	pop    %rax
  16:	f6 c4 02             	test   $0x2,%ah
  19:	75 37                	jne    0x52
  1b:	48 f7 04 24 00 02 00 	testq  $0x200,(%rsp)
  22:	00 
  23:	74 01                	je     0x26
  25:	fb                   	sti
  26:	48 83 c4 08          	add    $0x8,%rsp
  2a:*	44 89 e8             	mov    %r13d,%eax		<-- trapping instruction
  2d:	5b                   	pop    %rbx
  2e:	5d                   	pop    %rbp
  2f:	41 5c                	pop    %r12
  31:	41 5d                	pop    %r13
  33:	41 5e                	pop    %r14
  35:	41 5f                	pop    %r15
  37:	c3                   	ret
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	cc                   	int3
  3c:	45 31 ed             	xor    %r13d,%r13d
  3f:	eb                   	.byte 0xeb

Code starting with the faulting instruction
===========================================
   0:	44 89 e8             	mov    %r13d,%eax
   3:	5b                   	pop    %rbx
   4:	5d                   	pop    %rbp
   5:	41 5c                	pop    %r12
   7:	41 5d                	pop    %r13
   9:	41 5e                	pop    %r14
   b:	41 5f                	pop    %r15
   d:	c3                   	ret
   e:	cc                   	int3
   f:	cc                   	int3
  10:	cc                   	int3
  11:	cc                   	int3
  12:	45 31 ed             	xor    %r13d,%r13d
  15:	eb                   	.byte 0xeb
[  258.430333][    C2] RSP: 0018:ffffc900004c7ab8 EFLAGS: 00000286
[  258.430337][    C2] RAX: 0000000000000046 RBX: 0000000000000002 RCX: 0000000000000001
[  258.430338][    C2] RDX: 0000000000000000 RSI: ffffffffb035b5c0 RDI: ffff888009f82d70
[  258.430340][    C2] RBP: ffffffffb035b5c0 R08: ffffffffaebe791e R09: fffffbfff61b2c32
[  258.430342][    C2] R10: ffffc900004c7c88 R11: ffff888009f82300 R12: ffff888009f82300
[  258.430343][    C2] R13: 0000000000000000 R14: 00000000ffffffff R15: ffff888009f82d70
[ 258.430352][ C2] ? linkwatch_event (net/core/link_watch.c:286) 
[ 258.430368][ C2] __might_resched (kernel/sched/core.c:8729) 
[ 258.430379][ C2] __mutex_lock (./include/linux/kernel.h:73 kernel/locking/mutex.c:562 kernel/locking/mutex.c:730) 
[ 258.430390][ C2] ? linkwatch_event (net/core/link_watch.c:286) 
[ 258.430395][ C2] ? __pfx___mutex_lock (kernel/locking/mutex.c:729) 
[ 258.430404][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 258.430409][ C2] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 21)) 
[ 258.430411][ C2] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 21)) 
[ 258.430418][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 258.430427][ C2] ? linkwatch_event (net/core/link_watch.c:286) 
[ 258.430430][ C2] linkwatch_event (net/core/link_watch.c:286) 
[ 258.430433][ C2] process_one_work (kernel/workqueue.c:3238) 
[ 258.430447][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 258.430452][ C2] ? __pfx_process_one_work (kernel/workqueue.c:3140) 
[ 258.430465][ C2] ? assign_work (kernel/workqueue.c:1200) 
[ 258.430476][ C2] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400) 
[ 258.430481][ C2] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4349 kernel/locking/lockdep.c:4408) 
[ 258.430493][ C2] ? __pfx_worker_thread (kernel/workqueue.c:3346) 
[ 258.430499][ C2] kthread (kernel/kthread.c:464) 
[ 258.430504][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 258.430513][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 258.430519][ C2] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 258.430524][ C2] ? __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