======================================
| [ 13.729958][ C1] #3: ffff888006153358 (&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 
| [ 13.730432][ C1] #4: ffffffff9095b5c0 (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) 
| [   13.730757][    C1]
| [   13.730757][    C1] stack backtrace:
[   13.730999][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   13.731001][    C1] Workqueue: events_unbound linkwatch_event
[   13.731006][    C1] Call Trace:
[   13.731009][    C1]  <IRQ>
[ 13.731011][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 13.731019][ C1] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 13.731029][ C1] 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) 
[ 13.731040][ C1] __dev_queue_xmit (net/core/dev.h:340 net/core/dev.c:4631) 
[ 13.731051][ C1] ? __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) 
[ 13.731060][ C1] ? __pfx___dev_queue_xmit (net/core/dev.c:4538) 
[ 13.731063][ C1] ? __pfx___alloc_skb (net/core/skbuff.c:642) 
[ 13.731068][ C1] ? stack_trace_save (kernel/stacktrace.c:114) 
[ 13.731074][ C1] ? __pfx_stack_trace_save (kernel/stacktrace.c:114) 
[ 13.731082][ C1] ? __pfx___br_multicast_query_handle_vlan (net/bridge/br_multicast.c:909) bridge 
[ 13.731138][ C1] br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 13.731170][ C1] ? __pfx_br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 13.731203][ C1] ? 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 
[ 13.731243][ C1] __br_multicast_send_query (net/bridge/br_multicast.c:1813) bridge 
[ 13.731288][ C1] ? __pfx___br_multicast_send_query (net/bridge/br_multicast.c:1789) bridge 
[ 13.731328][ C1] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 13.731339][ C1] ? br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 13.731374][ C1] br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 13.731412][ C1] ? __pfx_br_multicast_send_query (net/bridge/br_multicast.c:1852) bridge 
[ 13.731445][ C1] ? 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 
[ 13.731482][ C1] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 13.731517][ C1] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 13.731523][ C1] ? 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) 
[ 13.731528][ C1] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 13.731532][ C1] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 13.731535][ C1] ? 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 
[ 13.731575][ C1] ? br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 13.731608][ C1] br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 13.731644][ C1] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 13.731677][ C1] call_timer_fn (kernel/time/timer.c:1789) 
[ 13.731681][ C1] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 13.731684][ C1] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 13.731688][ C1] ? __pfx_call_timer_fn (kernel/time/timer.c:1766) 
[ 13.731691][ C1] ? 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) 
[ 13.731700][ C1] ? mark_held_locks (kernel/locking/lockdep.c:4323) 
[ 13.731712][ C1] __run_timers (kernel/time/timer.c:1841 kernel/time/timer.c:2414) 
[ 13.731716][ C1] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 13.731758][ C1] ? __pfx___run_timers (kernel/time/timer.c:2385) 
[ 13.731761][ C1] ? clockevents_program_event (kernel/time/clockevents.c:326) 
[ 13.731771][ C1] ? 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) 
[ 13.731775][ C1] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 13.731779][ C1] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 13.731782][ C1] ? run_timer_softirq (kernel/time/timer.c:2426 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 13.731792][ C1] run_timer_softirq (kernel/time/timer.c:2427 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 13.731798][ C1] handle_softirqs (kernel/softirq.c:561) 
[ 13.731804][ C1] ? 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) 
[ 13.731812][ C1] __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) 
[ 13.731816][ C1] irq_exit_rcu (kernel/softirq.c:680) 
[ 13.731818][ C1] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   13.731822][    C1]  </IRQ>
[   13.731823][    C1]  <TASK>
[ 13.731826][ C1] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 13.731830][ C1] RIP: 0010:_raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 13.731834][ C1] Code: 10 e8 b1 3d 87 fd 48 89 ef e8 f9 ad 87 fd 81 e3 00 02 00 00 75 1d 9c 58 f6 c4 02 75 29 48 85 db 74 01 fb 65 ff 0d b5 0d 6f 70 <74> 0e 5b 5d c3 cc cc cc cc e8 2f df ac fd eb dc 0f 1f 44 00 00 5b
All code
========
   0:	10 e8                	adc    %ch,%al
   2:	b1 3d                	mov    $0x3d,%cl
   4:	87 fd                	xchg   %edi,%ebp
   6:	48 89 ef             	mov    %rbp,%rdi
   9:	e8 f9 ad 87 fd       	call   0xfffffffffd87ae07
   e:	81 e3 00 02 00 00    	and    $0x200,%ebx
  14:	75 1d                	jne    0x33
  16:	9c                   	pushf
  17:	58                   	pop    %rax
  18:	f6 c4 02             	test   $0x2,%ah
  1b:	75 29                	jne    0x46
  1d:	48 85 db             	test   %rbx,%rbx
  20:	74 01                	je     0x23
  22:	fb                   	sti
  23:	65 ff 0d b5 0d 6f 70 	decl   %gs:0x706f0db5(%rip)        # 0x706f0ddf
  2a:*	74 0e                	je     0x3a		<-- trapping instruction
  2c:	5b                   	pop    %rbx
  2d:	5d                   	pop    %rbp
  2e:	c3                   	ret
  2f:	cc                   	int3
  30:	cc                   	int3
  31:	cc                   	int3
  32:	cc                   	int3
  33:	e8 2f df ac fd       	call   0xfffffffffdacdf67
  38:	eb dc                	jmp    0x16
  3a:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  3f:	5b                   	pop    %rbx

Code starting with the faulting instruction
===========================================
   0:	74 0e                	je     0x10
   2:	5b                   	pop    %rbx
   3:	5d                   	pop    %rbp
   4:	c3                   	ret
   5:	cc                   	int3
   6:	cc                   	int3
   7:	cc                   	int3
   8:	cc                   	int3
   9:	e8 2f df ac fd       	call   0xfffffffffdacdf3d
   e:	eb dc                	jmp    0xffffffffffffffec
  10:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  15:	5b                   	pop    %rbx
[   13.731836][    C1] RSP: 0000:ffffc900002af9c0 EFLAGS: 00000282
[   13.731839][    C1] RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff254b35a
[   13.731841][    C1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8f94b761
[   13.731843][    C1] RBP: ffff888001a84f28 R08: 0000000000000001 R09: fffffbfff2545bed
[   13.731844][    C1] R10: ffffffff92a2df6f R11: ffff888001d82300 R12: ffff888036000000
[   13.731846][    C1] R13: 000000000003d7c0 R14: ffff888001a84f28 R15: 0000000000000088
[ 13.731859][ C1] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 13.731867][ C1] try_to_wake_up (./include/linux/spinlock.h:551 kernel/sched/core.c:4214) 
[ 13.731874][ C1] ? __pfx_try_to_wake_up (kernel/sched/core.c:4177) 
[ 13.731877][ C1] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 13.731890][ C1] wake_up_q (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:264 ./include/linux/refcount.h:307 ./include/linux/refcount.h:325 ./include/linux/sched/task.h:134 kernel/sched/core.c:1076) 
[ 13.731897][ C1] __mutex_unlock_slowpath (./include/linux/sched/wake_q.h:53 ./include/linux/sched/wake_q.h:97 kernel/locking/mutex.c:933) 
[ 13.731903][ C1] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:885) 
[ 13.731911][ C1] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 13.731914][ C1] ? 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) 
[ 13.731924][ C1] __rtnl_unlock (net/core/rtnetlink.c:145 (discriminator 3)) 
[ 13.731928][ C1] netdev_run_todo (./include/linux/list.h:373 net/core/dev.c:11274) 
[ 13.731933][ C1] ? _raw_spin_unlock_irq (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 ./include/linux/spinlock_api_smp.h:159 kernel/locking/spinlock.c:202) 
[ 13.731936][ C1] ? __linkwatch_run_queue (net/core/link_watch.c:195) 
[ 13.731941][ C1] ? __pfx_netdev_run_todo (net/core/dev.c:11251) 
[ 13.731951][ C1] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 13.731967][ C1] process_one_work (kernel/workqueue.c:3238) 
[ 13.731984][ C1] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 13.731989][ C1] ? __pfx_process_one_work (kernel/workqueue.c:3140) 
[ 13.732002][ C1] ? assign_work (kernel/workqueue.c:1200) 
[ 13.732013][ C1] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400) 
[ 13.732027][ C1] ? __pfx_worker_thread (kernel/workqueue.c:3346) 
[ 13.732034][ C1] kthread (kernel/kthread.c:464) 
[ 13.732038][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.732047][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.732053][ C1] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 13.732057][ C1] ? __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