======================================
| [ 92.862067][ C2] #4: ffff88800f71b358 (&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 
| [ 92.862582][ C2] #5: ffffffff9dd5b5c0 (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) 
| [   92.862982][    C2]
| [   92.862982][    C2] stack backtrace:
[   92.863272][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   92.863275][    C2] Workqueue: events_unbound linkwatch_event
[   92.863282][    C2] Call Trace:
[   92.863285][    C2]  <IRQ>
[ 92.863288][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 92.863297][ C2] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 92.863309][ 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) 
[ 92.863321][ C2] __dev_queue_xmit (net/core/dev.h:340 net/core/dev.c:4631) 
[ 92.863332][ 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) 
[ 92.863344][ C2] ? __pfx___dev_queue_xmit (net/core/dev.c:4538) 
[ 92.863346][ C2] ? __pfx___alloc_skb (net/core/skbuff.c:642) 
[ 92.863350][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 92.863360][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 92.863366][ C2] ? __pfx___br_multicast_query_handle_vlan (net/bridge/br_multicast.c:909) bridge 
[ 92.863420][ C2] br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 92.863450][ C2] ? hlock_class (kernel/locking/lockdep.c:225) 
[ 92.863455][ C2] ? __pfx_br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 92.863488][ 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 
[ 92.863527][ C2] __br_multicast_send_query (net/bridge/br_multicast.c:1813) bridge 
[ 92.863572][ C2] ? __pfx___br_multicast_send_query (net/bridge/br_multicast.c:1789) bridge 
[ 92.863612][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 92.863623][ C2] ? br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 92.863657][ C2] br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 92.863707][ C2] ? __pfx_br_multicast_send_query (net/bridge/br_multicast.c:1852) bridge 
[ 92.863740][ 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 
[ 92.863777][ C2] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 92.863812][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 92.863818][ 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) 
[ 92.863823][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 92.863826][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 92.863829][ 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 
[ 92.863869][ C2] ? br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 92.863902][ C2] br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 92.863938][ C2] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 92.863972][ C2] call_timer_fn (kernel/time/timer.c:1789) 
[ 92.863976][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 92.863978][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 92.863983][ C2] ? __pfx_call_timer_fn (kernel/time/timer.c:1766) 
[ 92.863986][ 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) 
[ 92.863995][ C2] ? mark_held_locks (kernel/locking/lockdep.c:4323) 
[ 92.864008][ C2] __run_timers (kernel/time/timer.c:1841 kernel/time/timer.c:2414) 
[ 92.864012][ C2] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 92.864056][ C2] ? __pfx___run_timers (kernel/time/timer.c:2385) 
[ 92.864059][ C2] ? clockevents_program_event (kernel/time/clockevents.c:326) 
[ 92.864069][ 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) 
[ 92.864073][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 92.864077][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 92.864080][ C2] ? run_timer_softirq (kernel/time/timer.c:2426 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 92.864091][ C2] run_timer_softirq (kernel/time/timer.c:2427 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 92.864096][ C2] handle_softirqs (kernel/softirq.c:561) 
[ 92.864109][ C2] __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) 
[ 92.864113][ C2] irq_exit_rcu (kernel/softirq.c:680) 
[ 92.864116][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   92.864121][    C2]  </IRQ>
[   92.864122][    C2]  <TASK>
[ 92.864125][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 92.864130][ C2] RIP: 0010:__orc_find (arch/x86/kernel/unwind_orc.c:106) 
[ 92.864136][ C2] Code: 00 48 89 da 48 c1 ea 03 0f b6 34 0a 48 89 da 83 e2 07 83 c2 03 40 38 f2 7c 05 40 84 f6 75 4b 48 63 13 48 01 da 49 39 d5 73 af <4c> 8d 63 fc 4c 39 e5 76 b2 4d 29 f7 49 c1 ff 02 4b 8d 14 7f 48 8d
All code
========
   0:	00 48 89             	add    %cl,-0x77(%rax)
   3:	da 48 c1             	fimull -0x3f(%rax)
   6:	ea                   	(bad)
   7:	03 0f                	add    (%rdi),%ecx
   9:	b6 34                	mov    $0x34,%dh
   b:	0a 48 89             	or     -0x77(%rax),%cl
   e:	da 83 e2 07 83 c2    	fiaddl -0x3d7cf81e(%rbx)
  14:	03 40 38             	add    0x38(%rax),%eax
  17:	f2 7c 05             	bnd jl 0x1f
  1a:	40 84 f6             	test   %sil,%sil
  1d:	75 4b                	jne    0x6a
  1f:	48 63 13             	movslq (%rbx),%rdx
  22:	48 01 da             	add    %rbx,%rdx
  25:	49 39 d5             	cmp    %rdx,%r13
  28:	73 af                	jae    0xffffffffffffffd9
  2a:*	4c 8d 63 fc          	lea    -0x4(%rbx),%r12		<-- trapping instruction
  2e:	4c 39 e5             	cmp    %r12,%rbp
  31:	76 b2                	jbe    0xffffffffffffffe5
  33:	4d 29 f7             	sub    %r14,%r15
  36:	49 c1 ff 02          	sar    $0x2,%r15
  3a:	4b 8d 14 7f          	lea    (%r15,%r15,2),%rdx
  3e:	48                   	rex.W
  3f:	8d                   	.byte 0x8d

Code starting with the faulting instruction
===========================================
   0:	4c 8d 63 fc          	lea    -0x4(%rbx),%r12
   4:	4c 39 e5             	cmp    %r12,%rbp
   7:	76 b2                	jbe    0xffffffffffffffbb
   9:	4d 29 f7             	sub    %r14,%r15
   c:	49 c1 ff 02          	sar    $0x2,%r15
  10:	4b 8d 14 7f          	lea    (%r15,%r15,2),%rdx
  14:	48                   	rex.W
  15:	8d                   	.byte 0x8d
[   92.864139][    C2] RSP: 0018:ffffc900005e74d8 EFLAGS: 00000283
[   92.864142][    C2] RAX: ffffffff9eec90a2 RBX: ffffffff9ea6aac4 RCX: dffffc0000000000
[   92.864144][    C2] RDX: ffffffff9c5e49e3 RSI: 0000000000000000 RDI: ffffffff9ea6aa7c
[   92.864146][    C2] RBP: ffffffff9ea6aabc R08: ffffc900005e7658 R09: 1ffff920000bceac
[   92.864148][    C2] R10: ffffc900005e7618 R11: ffffc900005e7659 R12: ffffffff9ea6aacc
[   92.864150][    C2] R13: ffffffff9c5e49da R14: ffffffff9ea6aa7c R15: ffffffff9ea6aab8
[ 92.864153][ C2] ? rtmsg_ifinfo (net/core/rtnetlink.c:4452 net/core/rtnetlink.c:4450) 
[ 92.864163][ C2] ? rtmsg_ifinfo (net/core/rtnetlink.c:4452) 
[ 92.864171][ C2] ? arch_stack_walk (arch/x86/kernel/stacktrace.c:24) 
[ 92.864181][ C2] unwind_next_frame (arch/x86/kernel/unwind_orc.c:495) 
[ 92.864186][ C2] ? rtmsg_ifinfo (net/core/rtnetlink.c:4452 net/core/rtnetlink.c:4450) 
[ 92.864191][ 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) 
[ 92.864196][ C2] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 92.864206][ C2] ? rtmsg_ifinfo (net/core/rtnetlink.c:4452 net/core/rtnetlink.c:4450) 
[ 92.864208][ C2] ? kernel_text_address (kernel/extable.c:99) 
[ 92.864214][ C2] ? __pfx_stack_trace_consume_entry (kernel/stacktrace.c:83) 
[ 92.864222][ C2] arch_stack_walk (arch/x86/kernel/stacktrace.c:24) 
[ 92.864234][ C2] ? rtmsg_ifinfo (net/core/rtnetlink.c:4452 net/core/rtnetlink.c:4450) 
[ 92.864242][ C2] stack_trace_save (kernel/stacktrace.c:123) 
[ 92.864247][ C2] ? __pfx_stack_trace_save (kernel/stacktrace.c:114) 
[ 92.864253][ C2] ? mark_held_locks (kernel/locking/lockdep.c:4323) 
[ 92.864262][ C2] set_track_prepare (mm/slub.c:935) 
[ 92.864267][ C2] ? kmalloc_reserve (net/core/skbuff.c:603) 
[ 92.864270][ C2] ? __alloc_skb (net/core/skbuff.c:669) 
[ 92.864272][ C2] ? rtmsg_ifinfo_build_skb (./include/linux/skbuff.h:1339 ./include/net/netlink.h:1019 net/core/rtnetlink.c:4399) 
[ 92.864275][ C2] ? rtmsg_ifinfo_event.part.0 (net/core/rtnetlink.c:4443) 
[ 92.864277][ C2] ? rtmsg_ifinfo (net/core/rtnetlink.c:4452 net/core/rtnetlink.c:4450) 
[ 92.864289][ C2] ___slab_alloc (mm/slub.c:966 mm/slub.c:3816) 
[ 92.864294][ C2] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 92.864297][ C2] ? __alloc_skb (net/core/skbuff.c:669) 
[ 92.864301][ C2] ? get_any_partial (./include/linux/seqlock.h:72 ./include/linux/cpuset.h:144 mm/slub.c:2909) 
[ 92.864321][ C2] ? __kmalloc_node_track_caller_noprof (mm/slub.c:3916 mm/slub.c:3991 mm/slub.c:4152 mm/slub.c:4293 mm/slub.c:4313) 
[ 92.864325][ C2] __kmalloc_node_track_caller_noprof (mm/slub.c:3916 mm/slub.c:3991 mm/slub.c:4152 mm/slub.c:4293 mm/slub.c:4313) 
[ 92.864329][ C2] ? __create_object (mm/kmemleak.c:766) 
[ 92.864336][ C2] ? __alloc_skb (net/core/skbuff.c:669) 
[ 92.864343][ C2] kmalloc_reserve (net/core/skbuff.c:603) 
[ 92.864352][ C2] __alloc_skb (net/core/skbuff.c:669) 
[ 92.864356][ C2] ? __pfx___alloc_skb (net/core/skbuff.c:642) 
[ 92.864365][ C2] ? rtnl_prop_list_size (net/core/rtnetlink.c:1233) 
[ 92.864375][ C2] ? if_nlmsg_size (net/core/rtnetlink.c:1326) 
[ 92.864387][ C2] rtmsg_ifinfo_build_skb (./include/linux/skbuff.h:1339 ./include/net/netlink.h:1019 net/core/rtnetlink.c:4399) 
[ 92.864398][ C2] rtmsg_ifinfo_event.part.0 (net/core/rtnetlink.c:4443) 
[ 92.864412][ C2] rtmsg_ifinfo (net/core/rtnetlink.c:4452 net/core/rtnetlink.c:4450) 
[ 92.864427][ C2] netdev_state_change (net/core/dev.c:1540) 
[ 92.864434][ C2] ? __pfx_netdev_state_change (net/core/dev.c:1530) 
[ 92.864450][ C2] linkwatch_do_dev (net/core/link_watch.c:186) 
[ 92.864455][ C2] __linkwatch_run_queue (./include/linux/spinlock.h:376 net/core/link_watch.c:245) 
[ 92.864462][ C2] ? __pfx___linkwatch_run_queue (net/core/link_watch.c:195) 
[ 92.864469][ C2] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 92.864479][ C2] linkwatch_event (net/core/link_watch.c:287) 
[ 92.864482][ C2] process_one_work (kernel/workqueue.c:3238) 
[ 92.864496][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 92.864502][ C2] ? __pfx_process_one_work (kernel/workqueue.c:3140) 
[ 92.864515][ C2] ? assign_work (kernel/workqueue.c:1200) 
[ 92.864526][ C2] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400) 
[ 92.864531][ C2] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4349 kernel/locking/lockdep.c:4408) 
[ 92.864543][ C2] ? __pfx_worker_thread (kernel/workqueue.c:3346) 
[ 92.864549][ C2] kthread (kernel/kthread.c:464) 
[ 92.864554][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 92.864563][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 92.864569][ C2] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 92.864574][ 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