======================================
| [ 1049.480866][   T11] veth_A-C: left allmulticast mode
| [ 1049.481028][   T11] veth_A-C: left promiscuous mode
| [ 1049.481305][   T11] br0: port 1(veth_A-C) entered disabled state
| [ 1609.357754][T10780] Initializing XFRM netlink socket
| [ 1857.007808][T12483] unregister_netdevice: waiting for veth_A-R1 to become free. Usage count = 5
[ 1857.008354][T12483] ref_tracker: veth_A-R1@ffff8880093515e0 has 2/4 users at
[1857.008354][T12483] dst_init (net/core/dst.c:53) 
[1857.008354][T12483] dst_alloc (net/core/dst.c:96) 
[1857.008354][T12483] ip6_dst_alloc (net/ipv6/route.c:342) 
[1857.008354][T12483] ip6_rt_pcpu_alloc (net/ipv6/route.c:1379) 
[1857.008354][T12483] ip6_pol_route (net/ipv6/route.c:1428 net/ipv6/route.c:2265) 
[1857.008354][T12483] fib6_rule_lookup (./include/net/ip6_fib.h:616 net/ipv6/fib6_rules.c:121) 
[1857.008354][T12483] ip6_route_output_flags (net/ipv6/route.c:2637 net/ipv6/route.c:2649) 
[1857.008354][T12483] ip6_dst_lookup_tail.constprop.0 (net/ipv6/ip6_output.c:1147) 
[1857.008354][T12483] ip6_dst_lookup_flow (net/ipv6/ip6_output.c:1251) 
[1857.008354][T12483] udp_tunnel6_dst_lookup (net/ipv6/ip6_udp_tunnel.c:165 net/ipv6/ip6_udp_tunnel.c:135) 
[1857.008354][T12483] vxlan_xmit_one (drivers/net/vxlan/vxlan_core.c:2524 (discriminator 4)) vxlan
[1857.008354][T12483] vxlan_xmit (drivers/net/vxlan/vxlan_core.c:2789) vxlan
[1857.008354][T12483] dev_hard_start_xmit (./include/linux/netdevice.h:4896 ./include/linux/netdevice.h:4910 net/core/dev.c:3581 net/core/dev.c:3597) 
[1857.008354][T12483] __dev_queue_xmit (net/core/dev.h:185 net/core/dev.c:4411) 
[1857.008354][T12483] ip6_finish_output2 (./include/net/neighbour.h:540 net/ipv6/ip6_output.c:137) 
[1857.008354][T12483] ip6_finish_output (net/ipv6/ip6_output.c:211 net/ipv6/ip6_output.c:222) 
| [1857.008354][T12483] dev_hard_start_xmit (./include/linux/netdevice.h:4896 ./include/linux/netdevice.h:4910 net/core/dev.c:3581 net/core/dev.c:3597) 
| [1857.008354][T12483] __dev_queue_xmit (net/core/dev.h:185 net/core/dev.c:4411) 
| [1857.008354][T12483] ip6_finish_output2 (./include/net/neighbour.h:540 net/ipv6/ip6_output.c:137) 
| [1857.008354][T12483] ip6_finish_output (net/ipv6/ip6_output.c:211 net/ipv6/ip6_output.c:222) 
| [ 1857.008354][T12483]
[ 1857.011370][T12483] ref_tracker: veth_A-R1@ffff8880093515e0 has 1/4 users at
[1857.011370][T12483] netdev_get_by_index (net/core/dev.c:917) 
[1857.011370][T12483] fib6_nh_init (net/ipv6/route.c:3541) 
[1857.011370][T12483] nh_create_ipv6 (net/ipv4/nexthop.c:2827) 
[1857.011370][T12483] nexthop_create (net/ipv4/nexthop.c:2878) 
[1857.011370][T12483] rtm_new_nexthop (net/ipv4/nexthop.c:2920 net/ipv4/nexthop.c:3206) 
[1857.011370][T12483] rtnetlink_rcv_msg (net/core/rtnetlink.c:6641) 
[1857.011370][T12483] netlink_rcv_skb (net/netlink/af_netlink.c:2550) 
[1857.011370][T12483] netlink_unicast (net/netlink/af_netlink.c:1331 net/netlink/af_netlink.c:1357) 
[1857.011370][T12483] netlink_sendmsg (net/netlink/af_netlink.c:1901) 
[1857.011370][T12483] ____sys_sendmsg (net/socket.c:730 net/socket.c:745 net/socket.c:2585) 
[1857.011370][T12483] ___sys_sendmsg (net/socket.c:2641) 
[1857.011370][T12483] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2670) 
[1857.011370][T12483] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[1857.011370][T12483] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
| [1857.011370][T12483] ___sys_sendmsg (net/socket.c:2641) 
| [1857.011370][T12483] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2670) 
| [1857.011370][T12483] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
| [1857.011370][T12483] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
| [ 1857.011370][T12483]
[ 1857.013548][T12483] ref_tracker: veth_A-R1@ffff8880093515e0 has 1/4 users at
[1857.013548][T12483] ipv6_add_dev (net/ipv6/addrconf.c:344 net/ipv6/addrconf.c:409) 
[1857.013548][T12483] addrconf_notify (net/ipv6/addrconf.c:3653) 
[1857.013548][T12483] notifier_call_chain (kernel/notifier.c:93 (discriminator 2)) 
[1857.013548][T12483] register_netdevice (./include/linux/notifier.h:207 net/core/dev.c:10455) 
[1857.013548][T12483] veth_newlink (drivers/net/veth.c:1860) 
[1857.013548][T12483] rtnl_newlink_create (net/core/rtnetlink.c:3510) 
[1857.013548][T12483] __rtnl_newlink (net/core/rtnetlink.c:3730) 
[1857.013548][T12483] rtnl_newlink (net/core/rtnetlink.c:3744) 
[1857.013548][T12483] rtnetlink_rcv_msg (net/core/rtnetlink.c:6641) 
[1857.013548][T12483] netlink_rcv_skb (net/netlink/af_netlink.c:2550) 
[1857.013548][T12483] netlink_unicast (net/netlink/af_netlink.c:1331 net/netlink/af_netlink.c:1357) 
[1857.013548][T12483] netlink_sendmsg (net/netlink/af_netlink.c:1901) 
[1857.013548][T12483] ____sys_sendmsg (net/socket.c:730 net/socket.c:745 net/socket.c:2585) 
[1857.013548][T12483] ___sys_sendmsg (net/socket.c:2641) 
[1857.013548][T12483] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2670) 
[1857.013548][T12483] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
| [1857.013548][T12483] ___sys_sendmsg (net/socket.c:2641) 
| [1857.013548][T12483] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2670) 
| [1857.013548][T12483] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
| [ 1857.013548][T12483]
| [ 1867.142728][T12483] unregister_netdevice: waiting for veth_A-R1 to become free. Usage count = 5
[ 1867.143126][T12483] ref_tracker: veth_A-R1@ffff8880093515e0 has 2/4 users at
[1867.143126][T12483] dst_init (net/core/dst.c:53) 
[1867.143126][T12483] dst_alloc (net/core/dst.c:96) 
[1867.143126][T12483] ip6_dst_alloc (net/ipv6/route.c:342) 
[1867.143126][T12483] ip6_rt_pcpu_alloc (net/ipv6/route.c:1379) 
[1867.143126][T12483] ip6_pol_route (net/ipv6/route.c:1428 net/ipv6/route.c:2265) 
[1867.143126][T12483] fib6_rule_lookup (./include/net/ip6_fib.h:616 net/ipv6/fib6_rules.c:121) 
[1867.143126][T12483] ip6_route_output_flags (net/ipv6/route.c:2637 net/ipv6/route.c:2649) 
[1867.143126][T12483] ip6_dst_lookup_tail.constprop.0 (net/ipv6/ip6_output.c:1147) 
[1867.143126][T12483] ip6_dst_lookup_flow (net/ipv6/ip6_output.c:1251) 
[1867.143126][T12483] udp_tunnel6_dst_lookup (net/ipv6/ip6_udp_tunnel.c:165 net/ipv6/ip6_udp_tunnel.c:135) 
[1867.143126][T12483] vxlan_xmit_one (drivers/net/vxlan/vxlan_core.c:2524 (discriminator 4)) vxlan
[1867.143126][T12483] vxlan_xmit (drivers/net/vxlan/vxlan_core.c:2789) vxlan
[1867.143126][T12483] dev_hard_start_xmit (./include/linux/netdevice.h:4896 ./include/linux/netdevice.h:4910 net/core/dev.c:3581 net/core/dev.c:3597) 
[1867.143126][T12483] __dev_queue_xmit (net/core/dev.h:185 net/core/dev.c:4411) 
[1867.143126][T12483] ip6_finish_output2 (./include/net/neighbour.h:540 net/ipv6/ip6_output.c:137) 
[1867.143126][T12483] ip6_finish_output (net/ipv6/ip6_output.c:211 net/ipv6/ip6_output.c:222) 
| [1867.143126][T12483] dev_hard_start_xmit (./include/linux/netdevice.h:4896 ./include/linux/netdevice.h:4910 net/core/dev.c:3581 net/core/dev.c:3597) 
| [1867.143126][T12483] __dev_queue_xmit (net/core/dev.h:185 net/core/dev.c:4411) 
| [1867.143126][T12483] ip6_finish_output2 (./include/net/neighbour.h:540 net/ipv6/ip6_output.c:137) 
| [1867.143126][T12483] ip6_finish_output (net/ipv6/ip6_output.c:211 net/ipv6/ip6_output.c:222) 
| [ 1867.143126][T12483]
[ 1867.145578][T12483] ref_tracker: veth_A-R1@ffff8880093515e0 has 1/4 users at
[1867.145578][T12483] netdev_get_by_index (net/core/dev.c:917) 
[1867.145578][T12483] fib6_nh_init (net/ipv6/route.c:3541) 
[1867.145578][T12483] nh_create_ipv6 (net/ipv4/nexthop.c:2827) 
[1867.145578][T12483] nexthop_create (net/ipv4/nexthop.c:2878) 
[1867.145578][T12483] rtm_new_nexthop (net/ipv4/nexthop.c:2920 net/ipv4/nexthop.c:3206) 
[1867.145578][T12483] rtnetlink_rcv_msg (net/core/rtnetlink.c:6641) 
[1867.145578][T12483] netlink_rcv_skb (net/netlink/af_netlink.c:2550) 
[1867.145578][T12483] netlink_unicast (net/netlink/af_netlink.c:1331 net/netlink/af_netlink.c:1357) 
[1867.145578][T12483] netlink_sendmsg (net/netlink/af_netlink.c:1901) 
[1867.145578][T12483] ____sys_sendmsg (net/socket.c:730 net/socket.c:745 net/socket.c:2585) 
[1867.145578][T12483] ___sys_sendmsg (net/socket.c:2641) 
[1867.145578][T12483] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2670) 
[1867.145578][T12483] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[1867.145578][T12483] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
| [1867.145578][T12483] ___sys_sendmsg (net/socket.c:2641) 
| [1867.145578][T12483] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2670) 
| [1867.145578][T12483] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
| [1867.145578][T12483] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
| [ 1867.145578][T12483]
[ 1867.147645][T12483] ref_tracker: veth_A-R1@ffff8880093515e0 has 1/4 users at
[1867.147645][T12483] ipv6_add_dev (net/ipv6/addrconf.c:344 net/ipv6/addrconf.c:409) 
[1867.147645][T12483] addrconf_notify (net/ipv6/addrconf.c:3653) 
[1867.147645][T12483] notifier_call_chain (kernel/notifier.c:93 (discriminator 2)) 
[1867.147645][T12483] register_netdevice (./include/linux/notifier.h:207 net/core/dev.c:10455) 
[1867.147645][T12483] veth_newlink (drivers/net/veth.c:1860) 
[1867.147645][T12483] rtnl_newlink_create (net/core/rtnetlink.c:3510) 
[1867.147645][T12483] __rtnl_newlink (net/core/rtnetlink.c:3730) 
[1867.147645][T12483] rtnl_newlink (net/core/rtnetlink.c:3744) 
[1867.147645][T12483] rtnetlink_rcv_msg (net/core/rtnetlink.c:6641) 
[1867.147645][T12483] netlink_rcv_skb (net/netlink/af_netlink.c:2550) 
[1867.147645][T12483] netlink_unicast (net/netlink/af_netlink.c:1331 net/netlink/af_netlink.c:1357) 
[1867.147645][T12483] netlink_sendmsg (net/netlink/af_netlink.c:1901) 
[1867.147645][T12483] ____sys_sendmsg (net/socket.c:730 net/socket.c:745 net/socket.c:2585) 
[1867.147645][T12483] ___sys_sendmsg (net/socket.c:2641) 
[1867.147645][T12483] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2670) 


Finger prints:
dst_init:dst_alloc:ip6_dst_alloc:ip6_rt_pcpu_alloc:ip6_pol_route
dev_hard_start_xmit:__dev_queue_xmit:ip6_finish_output2:ip6_finish_output:netdev_get_by_index
___sys_sendmsg:__sys_sendmsg:do_syscall_64:ipv6_add_dev:addrconf_notify
___sys_sendmsg:__sys_sendmsg:do_syscall_64:dst_init:dst_alloc
dev_hard_start_xmit:__dev_queue_xmit:ip6_finish_output2:ip6_finish_output:netdev_get_by_index
___sys_sendmsg:__sys_sendmsg:do_syscall_64:ipv6_add_dev:addrconf_notify