======================================
| [ 1350.615377][ C1] #4: ffff8880136bb358 (&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 
| [ 1350.615862][ C1] #5: 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) 
| [ 1350.616229][    C1]
| [ 1350.616229][    C1] stack backtrace:
[ 1350.616480][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1350.616483][    C1] Workqueue: events_unbound linkwatch_event
[ 1350.616487][    C1] Call Trace:
[ 1350.616489][    C1]  <IRQ>
[ 1350.616492][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 1350.616500][ C1] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 1350.616510][ 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) 
[ 1350.616521][ C1] __dev_queue_xmit (net/core/dev.h:340 net/core/dev.c:4631) 
[ 1350.616532][ 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) 
[ 1350.616542][ C1] ? __pfx___dev_queue_xmit (net/core/dev.c:4538) 
[ 1350.616545][ C1] ? __pfx___alloc_skb (net/core/skbuff.c:642) 
[ 1350.616548][ C1] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 1350.616558][ C1] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 1350.616564][ C1] ? __pfx___br_multicast_query_handle_vlan (net/bridge/br_multicast.c:909) bridge 
[ 1350.616615][ C1] br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 1350.616645][ C1] ? hlock_class (kernel/locking/lockdep.c:225) 
[ 1350.616649][ C1] ? __pfx_br_dev_queue_push_xmit (net/bridge/br_forward.c:34) bridge 
[ 1350.616682][ 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 
[ 1350.616721][ C1] __br_multicast_send_query (net/bridge/br_multicast.c:1813) bridge 
[ 1350.616766][ C1] ? __pfx___br_multicast_send_query (net/bridge/br_multicast.c:1789) bridge 
[ 1350.616806][ C1] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[ 1350.616817][ C1] ? br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 1350.616851][ C1] br_multicast_send_query (net/bridge/br_multicast.c:1891) bridge 
[ 1350.616890][ C1] ? __pfx_br_multicast_send_query (net/bridge/br_multicast.c:1852) bridge 
[ 1350.616923][ 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 
[ 1350.616960][ C1] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 1350.616997][ C1] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 1350.617003][ 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) 
[ 1350.617008][ C1] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 1350.617012][ C1] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 1350.617015][ 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 
[ 1350.617056][ C1] ? br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 1350.617089][ C1] br_multicast_port_query_expired (net/bridge/br_multicast.c:1917) bridge 
[ 1350.617125][ C1] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 1350.617159][ C1] call_timer_fn (kernel/time/timer.c:1789) 
[ 1350.617163][ C1] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 1350.617165][ C1] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1779) 
[ 1350.617170][ C1] ? __pfx_call_timer_fn (kernel/time/timer.c:1766) 
[ 1350.617173][ 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) 
[ 1350.617182][ C1] ? mark_held_locks (kernel/locking/lockdep.c:4323) 
[ 1350.617194][ C1] __run_timers (kernel/time/timer.c:1841 kernel/time/timer.c:2414) 
[ 1350.617198][ C1] ? __pfx_br_ip4_multicast_port_query_expired (net/bridge/br_multicast.c:1920) bridge 
[ 1350.617240][ C1] ? __pfx___run_timers (kernel/time/timer.c:2385) 
[ 1350.617243][ C1] ? clockevents_program_event (kernel/time/clockevents.c:326) 
[ 1350.617253][ 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) 
[ 1350.617257][ C1] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 1350.617261][ C1] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 1350.617264][ C1] ? run_timer_softirq (kernel/time/timer.c:2426 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 1350.617275][ C1] run_timer_softirq (kernel/time/timer.c:2427 kernel/time/timer.c:2418 kernel/time/timer.c:2435 kernel/time/timer.c:2445) 
[ 1350.617280][ C1] handle_softirqs (kernel/softirq.c:561) 
[ 1350.617293][ C1] __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) 
[ 1350.617296][ C1] irq_exit_rcu (kernel/softirq.c:680) 
[ 1350.617299][ C1] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 1350.617303][    C1]  </IRQ>
[ 1350.617304][    C1]  <TASK>
[ 1350.617307][ C1] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 1350.617311][ C1] RIP: 0010:__orc_find (arch/x86/kernel/unwind_orc.c:85) 
[ 1350.617315][ C1] Code: 90 90 90 90 90 48 8b 07 c3 cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 <41> 57 41 56 41 55 49 89 cd 89 d1 41 54 4c 8d 64 8f fc 55 53 48 83
All code
========
   0:	90                   	nop
   1:	90                   	nop
   2:	90                   	nop
   3:	90                   	nop
   4:	90                   	nop
   5:	48 8b 07             	mov    (%rdi),%rax
   8:	c3                   	ret
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
  14:	00 
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  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:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  2a:*	41 57                	push   %r15		<-- trapping instruction
  2c:	41 56                	push   %r14
  2e:	41 55                	push   %r13
  30:	49 89 cd             	mov    %rcx,%r13
  33:	89 d1                	mov    %edx,%ecx
  35:	41 54                	push   %r12
  37:	4c 8d 64 8f fc       	lea    -0x4(%rdi,%rcx,4),%r12
  3c:	55                   	push   %rbp
  3d:	53                   	push   %rbx
  3e:	48                   	rex.W
  3f:	83                   	.byte 0x83

Code starting with the faulting instruction
===========================================
   0:	41 57                	push   %r15
   2:	41 56                	push   %r14
   4:	41 55                	push   %r13
   6:	49 89 cd             	mov    %rcx,%r13
   9:	89 d1                	mov    %edx,%ecx
   b:	41 54                	push   %r12
   d:	4c 8d 64 8f fc       	lea    -0x4(%rdi,%rcx,4),%r12
  12:	55                   	push   %rbp
  13:	53                   	push   %rbx
  14:	48                   	rex.W
  15:	83                   	.byte 0x83
[ 1350.617318][    C1] RSP: 0018:ffffc900003df4a0 EFLAGS: 00000286
[ 1350.617321][    C1] RAX: 0000000000002a78 RBX: 0000000000000001 RCX: ffffffffac6afa79
[ 1350.617323][    C1] RDX: 0000000000000015 RSI: ffffffffb10f9de0 RDI: ffffffffb0de08ac
[ 1350.617324][    C1] RBP: ffffc900003df600 R08: ffffc900003df5e8 R09: 1ffff9200007be9e
[ 1350.617326][    C1] R10: ffffc900003df5a8 R11: ffffc900003df5e9 R12: 1ffff9200007be9e
[ 1350.617328][    C1] R13: ffffc900003df5a8 R14: 0000000000000000 R15: ffff8880019759c0
[ 1350.617338][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:244) 
[ 1350.617348][ C1] unwind_next_frame (arch/x86/kernel/unwind_orc.c:495) 
[ 1350.617352][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:257) 
[ 1350.617361][ C1] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 1350.617370][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:257) 
[ 1350.617373][ C1] ? kernel_text_address (kernel/extable.c:99) 
[ 1350.617377][ C1] ? __pfx_stack_trace_consume_entry (kernel/stacktrace.c:83) 
[ 1350.617385][ C1] arch_stack_walk (arch/x86/kernel/stacktrace.c:24) 
[ 1350.617397][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:257) 
[ 1350.617405][ C1] stack_trace_save (kernel/stacktrace.c:123) 
[ 1350.617410][ C1] ? __pfx_stack_trace_save (kernel/stacktrace.c:114) 
[ 1350.617423][ C1] kasan_save_stack (mm/kasan/common.c:48) 
[ 1350.617428][ C1] ? kasan_save_stack (mm/kasan/common.c:48) 
[ 1350.617431][ C1] ? kasan_save_track (./arch/x86/include/asm/current.h:49 mm/kasan/common.c:60 mm/kasan/common.c:69) 
[ 1350.617434][ C1] ? __kasan_slab_alloc (mm/kasan/common.c:348) 
[ 1350.617437][ C1] ? kmem_cache_alloc_node_noprof (mm/slub.c:4116 mm/slub.c:4164 mm/slub.c:4216) 
[ 1350.617442][ C1] ? __alloc_skb (net/core/skbuff.c:659) 
[ 1350.617444][ C1] ? inet6_ifinfo_notify (./include/linux/skbuff.h:1339 ./include/net/netlink.h:1019 net/ipv6/addrconf.c:6161) 
[ 1350.617448][ C1] ? addrconf_notify (net/ipv6/addrconf.c:3765 (discriminator 2)) 
[ 1350.617451][ C1] ? notifier_call_chain (kernel/notifier.c:85 (discriminator 2)) 
[ 1350.617456][ C1] ? netdev_state_change (net/core/dev.c:1538 net/core/dev.c:1529) 
[ 1350.617458][ C1] ? linkwatch_do_dev (net/core/link_watch.c:186) 
[ 1350.617461][ C1] ? __linkwatch_run_queue (./include/linux/spinlock.h:376 net/core/link_watch.c:245) 
[ 1350.617463][ C1] ? linkwatch_event (net/core/link_watch.c:287) 
[ 1350.617466][ C1] ? process_one_work (kernel/workqueue.c:3238) 
[ 1350.617468][ C1] ? worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400) 
[ 1350.617470][ C1] ? kthread (kernel/kthread.c:464) 
[ 1350.617472][ C1] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 1350.617476][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:257) 
[ 1350.617484][ C1] ? set_track_prepare (mm/slub.c:938) 
[ 1350.617487][ C1] ? __alloc_skb (net/core/skbuff.c:659) 
[ 1350.617489][ C1] ? inet6_ifinfo_notify (./include/linux/skbuff.h:1339 ./include/net/netlink.h:1019 net/ipv6/addrconf.c:6161) 
[ 1350.617492][ C1] ? addrconf_notify (net/ipv6/addrconf.c:3765 (discriminator 2)) 
[ 1350.617495][ C1] ? notifier_call_chain (kernel/notifier.c:85 (discriminator 2)) 
[ 1350.617498][ C1] ? netdev_state_change (net/core/dev.c:1538 net/core/dev.c:1529) 
[ 1350.617500][ C1] ? linkwatch_do_dev (net/core/link_watch.c:186) 
[ 1350.617502][ C1] ? __linkwatch_run_queue (./include/linux/spinlock.h:376 net/core/link_watch.c:245) 
[ 1350.617505][ C1] ? linkwatch_event (net/core/link_watch.c:287) 
[ 1350.617507][ C1] ? process_one_work (kernel/workqueue.c:3238) 
[ 1350.617509][ C1] ? worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400) 
[ 1350.617511][ C1] ? kthread (kernel/kthread.c:464) 
[ 1350.617513][ C1] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 1350.617516][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:257) 
[ 1350.617521][ C1] ? ___slab_alloc (mm/slub.c:967 mm/slub.c:3816) 
[ 1350.617526][ C1] ? __alloc_skb (net/core/skbuff.c:659) 
[ 1350.617530][ C1] ? get_any_partial (./include/linux/seqlock.h:72 ./include/linux/cpuset.h:144 mm/slub.c:2909) 
[ 1350.617538][ C1] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 1350.617541][ C1] ? __fib6_clean_all (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/ipv6/ip6_fib.c:2273) 
[ 1350.617546][ C1] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 1350.617549][ 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) 
[ 1350.617554][ C1] kasan_save_track (./arch/x86/include/asm/current.h:49 mm/kasan/common.c:60 mm/kasan/common.c:69) 
[ 1350.617558][ C1] __kasan_slab_alloc (mm/kasan/common.c:348) 
[ 1350.617564][ C1] kmem_cache_alloc_node_noprof (mm/slub.c:4116 mm/slub.c:4164 mm/slub.c:4216) 
[ 1350.617570][ C1] ? __fib6_clean_all (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/ipv6/ip6_fib.c:2273) 
[ 1350.617579][ C1] __alloc_skb (net/core/skbuff.c:659) 
[ 1350.617583][ C1] ? __pfx___alloc_skb (net/core/skbuff.c:642) 
[ 1350.617591][ C1] ? rt6_sync_up (net/ipv6/route.c:4797) 
[ 1350.617595][ C1] ? __pfx_rt6_sync_up (net/ipv6/route.c:4797) 
[ 1350.617603][ C1] inet6_ifinfo_notify (./include/linux/skbuff.h:1339 ./include/net/netlink.h:1019 net/ipv6/addrconf.c:6161) 
[ 1350.617609][ C1] addrconf_notify (net/ipv6/addrconf.c:3765 (discriminator 2)) 
[ 1350.617617][ C1] notifier_call_chain (kernel/notifier.c:85 (discriminator 2)) 
[ 1350.617628][ C1] netdev_state_change (net/core/dev.c:1538 net/core/dev.c:1529) 
[ 1350.617632][ C1] ? __pfx_netdev_state_change (net/core/dev.c:1530) 
[ 1350.617648][ C1] linkwatch_do_dev (net/core/link_watch.c:186) 
[ 1350.617652][ C1] __linkwatch_run_queue (./include/linux/spinlock.h:376 net/core/link_watch.c:245) 
[ 1350.617659][ C1] ? __pfx___linkwatch_run_queue (net/core/link_watch.c:195) 
[ 1350.617665][ C1] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 1350.617675][ C1] linkwatch_event (net/core/link_watch.c:287) 
[ 1350.617678][ C1] process_one_work (kernel/workqueue.c:3238) 
[ 1350.617691][ C1] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 1350.617697][ C1] ? __pfx_process_one_work (kernel/workqueue.c:3140) 
[ 1350.617710][ C1] ? assign_work (kernel/workqueue.c:1200) 
[ 1350.617719][ C1] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400) 
[ 1350.617733][ C1] ? __pfx_worker_thread (kernel/workqueue.c:3346) 
[ 1350.617739][ C1] kthread (kernel/kthread.c:464) 
[ 1350.617744][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 1350.617752][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 1350.617758][ C1] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 1350.617761][ 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