======================================
| [ 3172.607885][   T75] veth_A-C (unregistering): left promiscuous mode
| [ 3184.637533][T14784] geneve_a: left promiscuous mode
| [ 3189.694654][T14798] ovs_br0: left promiscuous mode
| [ 4015.075034][T19299] Initializing XFRM netlink socket
| [ 4492.410216][T21692] unregister_netdevice: waiting for veth_A-R1 to become free. Usage count = 6
[ 4492.410759][T21692] ref_tracker: veth_A-R1@ffff88800848c5e0 has 1/5 users at
[4492.410759][T21692] dst_init (net/core/dst.c:53) 
[4492.410759][T21692] dst_alloc (net/core/dst.c:96) 
[4492.410759][T21692] ip6_dst_alloc (net/ipv6/route.c:342) 
[4492.410759][T21692] ip6_rt_pcpu_alloc (net/ipv6/route.c:1381) 
[4492.410759][T21692] ip6_pol_route (net/ipv6/route.c:1430 net/ipv6/route.c:2267) 
[4492.410759][T21692] fib6_rule_lookup (./include/net/ip6_fib.h:616 net/ipv6/fib6_rules.c:121) 
[4492.410759][T21692] ip6_route_output_flags (net/ipv6/route.c:2639 net/ipv6/route.c:2651) 
[4492.410759][T21692] ip6_dst_lookup_tail.constprop.0 (net/ipv6/ip6_output.c:1148) 
[4492.410759][T21692] ip6_dst_lookup_flow (net/ipv6/ip6_output.c:1252) 
[4492.410759][T21692] udp_tunnel6_dst_lookup (net/ipv6/ip6_udp_tunnel.c:165 net/ipv6/ip6_udp_tunnel.c:135) 
[4492.410759][T21692] vxlan_xmit_one (drivers/net/vxlan/vxlan_core.c:2531 (discriminator 4)) vxlan
[4492.410759][T21692] vxlan_xmit (drivers/net/vxlan/vxlan_core.c:2796) vxlan
[4492.410759][T21692] dev_hard_start_xmit (./include/linux/netdevice.h:4881 ./include/linux/netdevice.h:4890 net/core/dev.c:3580 net/core/dev.c:3596) 
[4492.410759][T21692] __dev_queue_xmit (net/core/dev.h:168 net/core/dev.c:4424) 
[4492.410759][T21692] arp_solicit (net/ipv4/arp.c:392) 
[4492.410759][T21692] neigh_probe (net/core/neighbour.c:1077) 
| [4492.410759][T21692] dev_hard_start_xmit (./include/linux/netdevice.h:4881 ./include/linux/netdevice.h:4890 net/core/dev.c:3580 net/core/dev.c:3596) 
| [4492.410759][T21692] __dev_queue_xmit (net/core/dev.h:168 net/core/dev.c:4424) 
| [4492.410759][T21692] arp_solicit (net/ipv4/arp.c:392) 
| [4492.410759][T21692] neigh_probe (net/core/neighbour.c:1077) 
| [ 4492.410759][T21692]
[ 4492.413796][T21692] ref_tracker: veth_A-R1@ffff88800848c5e0 has 2/5 users at
[4492.413796][T21692] dst_init (net/core/dst.c:53) 
[4492.413796][T21692] dst_alloc (net/core/dst.c:96) 
[4492.413796][T21692] ip6_dst_alloc (net/ipv6/route.c:342) 
[4492.413796][T21692] ip6_rt_pcpu_alloc (net/ipv6/route.c:1381) 
[4492.413796][T21692] ip6_pol_route (net/ipv6/route.c:1430 net/ipv6/route.c:2267) 
[4492.413796][T21692] fib6_rule_lookup (./include/net/ip6_fib.h:616 net/ipv6/fib6_rules.c:121) 
[4492.413796][T21692] ip6_route_output_flags (net/ipv6/route.c:2639 net/ipv6/route.c:2651) 
[4492.413796][T21692] ip6_dst_lookup_tail.constprop.0 (net/ipv6/ip6_output.c:1148) 
[4492.413796][T21692] ip6_dst_lookup_flow (net/ipv6/ip6_output.c:1252) 
[4492.413796][T21692] udp_tunnel6_dst_lookup (net/ipv6/ip6_udp_tunnel.c:165 net/ipv6/ip6_udp_tunnel.c:135) 
[4492.413796][T21692] vxlan_xmit_one (drivers/net/vxlan/vxlan_core.c:2531 (discriminator 4)) vxlan
[4492.413796][T21692] vxlan_xmit (drivers/net/vxlan/vxlan_core.c:2796) vxlan
[4492.413796][T21692] dev_hard_start_xmit (./include/linux/netdevice.h:4881 ./include/linux/netdevice.h:4890 net/core/dev.c:3580 net/core/dev.c:3596) 
[4492.413796][T21692] __dev_queue_xmit (net/core/dev.h:168 net/core/dev.c:4424) 
[4492.413796][T21692] ip6_finish_output2 (./include/net/neighbour.h:540 net/ipv6/ip6_output.c:137) 
[4492.413796][T21692] ip6_finish_output (net/ipv6/ip6_output.c:211 net/ipv6/ip6_output.c:222) 
| [4492.413796][T21692] dev_hard_start_xmit (./include/linux/netdevice.h:4881 ./include/linux/netdevice.h:4890 net/core/dev.c:3580 net/core/dev.c:3596) 
| [4492.413796][T21692] __dev_queue_xmit (net/core/dev.h:168 net/core/dev.c:4424) 
| [4492.413796][T21692] ip6_finish_output2 (./include/net/neighbour.h:540 net/ipv6/ip6_output.c:137) 
| [4492.413796][T21692] ip6_finish_output (net/ipv6/ip6_output.c:211 net/ipv6/ip6_output.c:222) 
| [ 4492.413796][T21692]
[ 4492.416337][T21692] ref_tracker: veth_A-R1@ffff88800848c5e0 has 1/5 users at
[4492.416337][T21692] netdev_get_by_index (net/core/dev.c:916) 
[4492.416337][T21692] fib6_nh_init (net/ipv6/route.c:3543) 
[4492.416337][T21692] nh_create_ipv6 (net/ipv4/nexthop.c:2843) 
[4492.416337][T21692] nexthop_create (net/ipv4/nexthop.c:2894) 
[4492.416337][T21692] rtm_new_nexthop (net/ipv4/nexthop.c:2936 net/ipv4/nexthop.c:3222) 
[4492.416337][T21692] rtnetlink_rcv_msg (net/core/rtnetlink.c:6647) 
[4492.416337][T21692] netlink_rcv_skb (net/netlink/af_netlink.c:2550) 
[4492.416337][T21692] netlink_unicast (net/netlink/af_netlink.c:1331 net/netlink/af_netlink.c:1357) 
[4492.416337][T21692] netlink_sendmsg (net/netlink/af_netlink.c:1901) 
[4492.416337][T21692] ____sys_sendmsg (net/socket.c:730 net/socket.c:745 net/socket.c:2597) 
[4492.416337][T21692] ___sys_sendmsg (net/socket.c:2653) 
[4492.416337][T21692] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2682) 
[4492.416337][T21692] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[4492.416337][T21692] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
| [4492.416337][T21692] ___sys_sendmsg (net/socket.c:2653) 
| [4492.416337][T21692] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2682) 
| [4492.416337][T21692] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
| [4492.416337][T21692] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
| [ 4492.416337][T21692]
[ 4492.418485][T21692] ref_tracker: veth_A-R1@ffff88800848c5e0 has 1/5 users at
[4492.418485][T21692] ipv6_add_dev (net/ipv6/addrconf.c:344 net/ipv6/addrconf.c:409) 
[4492.418485][T21692] addrconf_notify (net/ipv6/addrconf.c:3656) 
[4492.418485][T21692] notifier_call_chain (kernel/notifier.c:93 (discriminator 2)) 
[4492.418485][T21692] register_netdevice (./include/linux/notifier.h:207 net/core/dev.c:10478) 
[4492.418485][T21692] veth_newlink (drivers/net/veth.c:1861) 
[4492.418485][T21692] rtnl_newlink_create (net/core/rtnetlink.c:3510) 
[4492.418485][T21692] __rtnl_newlink (net/core/rtnetlink.c:3730) 
[4492.418485][T21692] rtnl_newlink (net/core/rtnetlink.c:3744) 
[4492.418485][T21692] rtnetlink_rcv_msg (net/core/rtnetlink.c:6647) 
[4492.418485][T21692] netlink_rcv_skb (net/netlink/af_netlink.c:2550) 
[4492.418485][T21692] netlink_unicast (net/netlink/af_netlink.c:1331 net/netlink/af_netlink.c:1357) 
[4492.418485][T21692] netlink_sendmsg (net/netlink/af_netlink.c:1901) 
[4492.418485][T21692] ____sys_sendmsg (net/socket.c:730 net/socket.c:745 net/socket.c:2597) 
[4492.418485][T21692] ___sys_sendmsg (net/socket.c:2653) 
[4492.418485][T21692] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2682) 


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