======================================
| [   32.460153][   T49] br1: port 2(veth2) entered forwarding state
| [   32.465220][    C3] ------------[ cut here ]------------
| [   32.465618][    C3] UBSAN: invalid-load in ./include/linux/skbuff.h:4267:9
| [   32.465981][    C3] load of value 107 is not a valid value for type '_Bool'
[   32.466754][    C3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   32.467402][    C3] Workqueue: mld mld_ifc_work
[   32.467654][    C3] Call Trace:
[   32.467830][    C3]  <IRQ>
[ 32.467990][ C3] dump_stack_lvl (lib/dump_stack.c:107) 
[ 32.468233][ C3] __ubsan_handle_load_invalid_value (lib/ubsan.c:218 lib/ubsan.c:419) 
[ 32.468561][ C3] br_forward_finish.cold (./include/linux/spinlock.h:396 net/bridge/br.c:81) bridge
[ 32.469001][ C3] deliver_clone (net/bridge/br_forward.c:132) bridge
[ 32.469342][ C3] br_handle_frame_finish (net/bridge/br_input.c:215) bridge
[   32.46
DETECTED CRASH, lowering timeout
9726][ C3] ? __pfx_br_handle_frame_finish (net/bridge/br_input.c:75) bridge
[ 32.470153][ C3] ? 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:228) 
[ 32.470408][ C3] ? __pfx_nf_ingress (net/core/dev.c:5324) 
[ 32.470688][ C3] br_handle_frame (net/bridge/br_input.c:417) bridge
[ 32.471013][ C3] ? __pfx_br_handle_frame (net/bridge/br_input.c:321) bridge
[ 32.471365][ C3] __netif_receive_skb_core.constprop.0 (net/core/dev.c:5448) 
[ 32.471717][ C3] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 32.471951][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 32.472213][ C3] ? __pfx___netif_receive_skb_core.constprop.0 (net/core/dev.c:5341) 
[ 32.472590][ C3] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 32.472861][ C3] ? process_backlog (./include/linux/rcupdate.h:298 ./include/linux/rcupdate.h:750 net/core/dev.c:5995) 
[ 32.473122][ C3] __netif_receive_skb_one_core (net/core/dev.c:5553) 
[ 32.473425][ C3] ? __pfx___netif_receive_skb_one_core (net/core/dev.c:5547) 
[ 32.473761][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 32.474005][ C3] ? process_backlog (./include/linux/rcupdate.h:298 ./include/linux/rcupdate.h:750 net/core/dev.c:5995) 
[ 32.474269][ C3] process_backlog (./include/linux/rcupdate.h:779 net/core/dev.c:5997) 
[ 32.474525][ C3] __napi_poll.constprop.0 (net/core/dev.c:6625) 
[ 32.474809][ C3] net_rx_action (net/core/dev.c:6694 net/core/dev.c:6827) 
[ 32.475112][ C3] ? __pfx_net_rx_action (net/core/dev.c:6791) 
[ 32.475410][ C3] ? hlock_class (kernel/locking/lockdep.c:223) 
[ 32.475672][ C3] ? mark_held_locks (kernel/locking/lockdep.c:4274) 
[ 32.475930][ C3] __do_softirq (kernel/softirq.c:553) 
[ 32.476189][ C3] ? __dev_queue_xmit (./include/linux/rcupdate.h:308 ./include/linux/rcupdate.h:818 net/core/dev.c:4364) 
[ 32.476459][ C3] do_softirq (kernel/softirq.c:454 kernel/softirq.c:441) 
[   32.476702][    C3]  </IRQ>
[   32.476873][    C3]  <TASK>
[ 32.477029][ C3] __local_bh_enable_ip (kernel/softirq.c:381) 
[ 32.477333][ C3] ? __dev_queue_xmit (./include/linux/rcupdate.h:308 ./include/linux/rcupdate.h:818 net/core/dev.c:4364) 
[ 32.477634][ C3] __dev_queue_xmit (net/core/dev.c:4365) 
[ 32.477897][ C3] ? mark_held_locks (kernel/locking/lockdep.c:4274) 
[ 32.478170][ C3] ? eth_header (net/ethernet/eth.c:100) 
[ 32.478417][ C3] ? __pfx___dev_queue_xmit (net/core/dev.c:4246) 
[ 32.478720][ C3] ? neigh_resolve_output (./include/linux/netdevice.h:3226 net/core/neighbour.c:1558 net/core/neighbour.c:1543) 
[ 32.479055][ C3] ip6_finish_output2 (./include/net/neighbour.h:542 net/ipv6/ip6_output.c:137) 
[ 32.479348][ C3] ip6_finish_output (net/ipv6/ip6_output.c:211 net/ipv6/ip6_output.c:222) 
[ 32.479613][ C3] ip6_output (./include/linux/netfilter.h:303 net/ipv6/ip6_output.c:243) 
[ 32.479856][ C3] ? __pfx_ip6_output (net/ipv6/ip6_output.c:230) 
[ 32.480113][ C3] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 32.480386][ C3] ? 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:228) 
[ 32.480624][ C3] ? __lock_release (kernel/locking/lockdep.c:353 kernel/locking/lockdep.c:5436) 
[ 32.480885][ C3] NF_HOOK.constprop.0 (./include/linux/rcupdate.h:298 ./include/linux/rcupdate.h:750 ./include/linux/netfilter.h:238 ./include/linux/netfilter.h:312) 
[ 32.481154][ C3] ? __pfx_NF_HOOK.constprop.0 (./include/linux/netfilter.h:308) 
[ 32.481445][ C3] ? __pfx_xfrm_lookup_with_ifid (net/xfrm/xfrm_policy.c:3133) 
[ 32.481751][ C3] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 32.482089][ C3] ? icmp6_dst_alloc (net/ipv6/route.c:3292) 
[ 32.482347][ C3] ? __local_bh_enable_ip (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:77 kernel/softirq.c:386) 
[ 32.482627][ C3] mld_sendpack (net/ipv6/mcast.c:1822) 
[ 32.482871][ C3] ? __pfx_mld_sendpack (net/ipv6/mcast.c:1779) 
[ 32.483142][ C3] ? mld_send_cr (net/ipv6/mcast.c:2096 (discriminator 11)) 
[ 32.483388][ C3] mld_ifc_work (net/ipv6/mcast.c:2652) 
[ 32.483655][ C3] process_one_work (kernel/workqueue.c:2633) 
[ 32.483942][ C3] ? 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:228) 
[ 32.484201][ C3] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 32.484505][ C3] ? assign_work (kernel/workqueue.c:1101) 
[ 32.484766][ C3] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 32.485034][ C3] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 32.485390][ C3] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 32.485659][ C3] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 32.485924][ C3] kthread (kernel/kthread.c:388) 
[ 32.486159][ C3] ? __pfx_kthread (kernel/kthread.c:341) 
[ 32.486410][ C3] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 32.486659][ C3] ? __pfx_kthread (kernel/kthread.c:341) 


Finger prints:
dump_stack_lvl:__ubsan_handle_load_invalid_value:deliver_clone:br_handle_frame_finish