======================================
| [ 14.817896][ C2] #6: ffff88800badb358 (&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 
| [ 14.818479][ C2] #7: ffffffffa935b5c0 (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) 
| [   14.818920][    C2]
| [   14.818920][    C2] stack backtrace:
[   14.819232][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   14.819234][    C2] Workqueue: events_unbound linkwatch_event
[   14.819241][    C2] Call Trace:
[   14.819243][    C2]  <IRQ>
[ 14.819246][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 14.819253][ C2] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 14.819264][ 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) 
[ 14.819276][ C2] __dev_queue_xmit (net/core/dev.h:340 net/core/dev.c:4631) 
[ 14.819290][ 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) 
[ 14.819304][ C2] ? __pfx___dev_queue_xmit (net/core/dev.c:4538) 
[ 14.819310][ C2] ? __pfx___alloc_skb (net/core/skbuff.c:642) 
[ 14.819320][ C2] ? stack_trace_save (kernel/stacktrace.c:114) 
[ 14.819326][ C2] ? __pfx_stack_trace_save (kernel/stacktrace.c:114) 
[ 14.819334][ C2] ? __pfx___br_multicast_query_handle_vlan (net/bridge/br_multicast.c:909) bridge 
[ 14.819395][ C2] br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 14.819433][ C2] ? __pfx_br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 14.819489][ 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 
[ 14.819534][ C2] __br_multicast_send_query (net/bridge/br_multicast.c:1813) bridge 
[ 14.819586][ C2] ? __pfx___br_multicast_send_query (net/bridge/br_multicast.c:1789) bridge 
[ 14.819637][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 14.819654][ C2] ? br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 14.819700][ C2] br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 14.819754][ C2] ? __pfx_br_multicast_send_query (net/bridge/br_multicast.c:1852) bridge 
[ 14.819790][ 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 
[ 14.819828][ C2] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 14.819862][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 14.819869][ 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) 
[ 14.819874][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 14.819878][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 14.819881][ 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 
[ 14.819921][ C2] ? br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 14.819954][ C2] br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 14.819991][ C2] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 14.820024][ C2] call_timer_fn (kernel/time/timer.c:1789) 
[ 14.820029][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 14.820031][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 14.820036][ C2] ? __pfx_call_timer_fn (kernel/time/timer.c:1766) 
[ 14.820039][ 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) 
[ 14.820049][ C2] ? mark_held_locks (kernel/locking/lockdep.c:4323) 
[ 14.820061][ C2] __run_timers (kernel/time/timer.c:1841 kernel/time/timer.c:2414) 
[ 14.820065][ C2] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 14.820110][ C2] ? __pfx___run_timers (kernel/time/timer.c:2385) 
[ 14.820114][ C2] ? clockevents_program_event (kernel/time/clockevents.c:326) 
[ 14.820129][ 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) 
[ 14.820137][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 14.820143][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 14.820146][ C2] ? run_timer_softirq (kernel/time/timer.c:2426 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 14.820162][ C2] run_timer_softirq (kernel/time/timer.c:2427 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 14.820170][ C2] handle_softirqs (kernel/softirq.c:561) 
[ 14.820191][ C2] __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) 
[ 14.820198][ C2] irq_exit_rcu (kernel/softirq.c:680) 
[ 14.820201][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   14.820210][    C2]  </IRQ>
[   14.820211][    C2]  <TASK>
[ 14.820215][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 14.820223][ C2] RIP: 0010:lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 14.820229][ C2] Code: ff 48 83 c4 28 65 0f c1 05 f4 91 46 5a 83 f8 01 0f 85 b5 01 00 00 9c 58 f6 c4 02 0f 85 be 01 00 00 48 85 ed 0f 85 9b 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7
All code
========
   0:	ff 48 83             	decl   -0x7d(%rax)
   3:	c4                   	(bad)
   4:	28 65 0f             	sub    %ah,0xf(%rbp)
   7:	c1 05 f4 91 46 5a 83 	roll   $0x83,0x5a4691f4(%rip)        # 0x5a469202
   e:	f8                   	clc
   f:	01 0f                	add    %ecx,(%rdi)
  11:	85 b5 01 00 00 9c    	test   %esi,-0x63ffffff(%rbp)
  17:	58                   	pop    %rax
  18:	f6 c4 02             	test   $0x2,%ah
  1b:	0f 85 be 01 00 00    	jne    0x1df
  21:	48 85 ed             	test   %rbp,%rbp
  24:	0f 85 9b 01 00 00    	jne    0x1c5
  2a:*	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax		<-- trapping instruction
  31:	fc ff df 
  34:	48 01 c3             	add    %rax,%rbx
  37:	48 c7 03 00 00 00 00 	movq   $0x0,(%rbx)
  3e:	48                   	rex.W
  3f:	c7                   	.byte 0xc7

Code starting with the faulting instruction
===========================================
   0:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   7:	fc ff df 
   a:	48 01 c3             	add    %rax,%rbx
   d:	48 c7 03 00 00 00 00 	movq   $0x0,(%rbx)
  14:	48                   	rex.W
  15:	c7                   	.byte 0xc7
[   14.820233][    C2] RSP: 0018:ffffc900003df7d8 EFLAGS: 00000206
[   14.820237][    C2] RAX: 0000000000000046 RBX: 1ffff9200007befe RCX: 0000000000000001
[   14.820239][    C2] RDX: 1ffff11000994a00 RSI: 00000000ffffffff RDI: ffff888004ca50ca
[   14.820240][    C2] RBP: 0000000000000200 R08: 0000000000000001 R09: fffffbfff5685be2
[   14.820242][    C2] R10: ffffffffab42df17 R11: ffff888004ca45c0 R12: ffffffffa95432e0
[   14.820244][    C2] R13: ffff8880010433c0 R14: 00000000ffffffff R15: 0000000000001000
[ 14.820263][ C2] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 14.820266][ C2] ? __create_object (mm/kmemleak.c:766) 
[ 14.820272][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 14.820277][ C2] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 21)) 
[ 14.820280][ C2] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[ 14.820288][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 14.820291][ C2] ? fs_reclaim_acquire (mm/page_alloc.c:3867 mm/page_alloc.c:3858) 
[ 14.820296][ C2] ? fs_reclaim_acquire (mm/page_alloc.c:3867 mm/page_alloc.c:3858) 
[ 14.820300][ C2] ? fs_reclaim_acquire (mm/page_alloc.c:3867 mm/page_alloc.c:3858) 
[ 14.820304][ C2] fs_reclaim_acquire (mm/page_alloc.c:3868 mm/page_alloc.c:3858) 
[ 14.820306][ C2] ? fs_reclaim_acquire (mm/page_alloc.c:3867 mm/page_alloc.c:3858) 
[ 14.820310][ C2] __kmalloc_node_track_caller_noprof (./include/linux/sched/mm.h:319 mm/slub.c:4066 mm/slub.c:4144 mm/slub.c:4293 mm/slub.c:4313) 
[ 14.820315][ C2] ? __create_object (mm/kmemleak.c:766) 
[ 14.820320][ C2] ? __alloc_skb (net/core/skbuff.c:669) 
[ 14.820328][ C2] kmalloc_reserve (net/core/skbuff.c:603) 
[ 14.820337][ C2] __alloc_skb (net/core/skbuff.c:669) 
[ 14.820342][ C2] ? __pfx___alloc_skb (net/core/skbuff.c:642) 
[ 14.820349][ C2] ? rtnl_prop_list_size (net/core/rtnetlink.c:1233) 
[ 14.820357][ C2] ? if_nlmsg_size (net/core/rtnetlink.c:1326) 
[ 14.820366][ C2] rtmsg_ifinfo_build_skb (./include/linux/skbuff.h:1339 ./include/net/netlink.h:1019 net/core/rtnetlink.c:4399) 
[ 14.820376][ C2] rtmsg_ifinfo_event.part.0 (net/core/rtnetlink.c:4443) 
[ 14.820385][ C2] rtmsg_ifinfo (net/core/rtnetlink.c:4452 net/core/rtnetlink.c:4450) 
[ 14.820394][ C2] netdev_state_change (net/core/dev.c:1540) 
[ 14.820399][ C2] ? __pfx_netdev_state_change (net/core/dev.c:1530) 
[ 14.820414][ C2] linkwatch_do_dev (net/core/link_watch.c:186) 
[ 14.820419][ C2] __linkwatch_run_queue (./include/linux/spinlock.h:376 net/core/link_watch.c:245) 
[ 14.820426][ C2] ? __pfx___linkwatch_run_queue (net/core/link_watch.c:195) 
[ 14.820433][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 14.820443][ C2] linkwatch_event (net/core/link_watch.c:287) 
[ 14.820446][ C2] process_one_work (kernel/workqueue.c:3238) 
[ 14.820460][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 14.820465][ C2] ? __pfx_process_one_work (kernel/workqueue.c:3140) 
[ 14.820479][ C2] ? assign_work (kernel/workqueue.c:1200) 
[ 14.820489][ C2] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400) 
[ 14.820503][ C2] ? __pfx_worker_thread (kernel/workqueue.c:3346) 
[ 14.820510][ C2] kthread (kernel/kthread.c:464) 
[ 14.820515][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 14.820524][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 14.820530][ C2] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 14.820535][ 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