unregister_netdevice: waiting for lo to become free. Usage count = 120
ref_tracker: lo@ffff888068c34620 has 119/119 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4062 [inline]
     netdev_hold include/linux/netdevice.h:4091 [inline]
     dst_init+0xee/0x490 net/core/dst.c:52
     dst_alloc+0x14f/0x190 net/core/dst.c:93
     rt_dst_clone+0x52/0x650 net/ipv4/route.c:1640
     ip_mc_finish_output+0x102/0x570 net/ipv4/ip_output.c:356
     NF_HOOK include/linux/netfilter.h:314 [inline]
     ip_mc_output+0x279/0x5c0 net/ipv4/ip_output.c:400
     ip_local_out net/ipv4/ip_output.c:130 [inline]
     ip_send_skb+0x74/0x100 net/ipv4/ip_output.c:1496
     udp_send_skb+0xab6/0x1630 net/ipv4/udp.c:984
     udp_sendmsg+0x1c21/0x2a60 net/ipv4/udp.c:1272
     sock_sendmsg_nosec net/socket.c:729 [inline]
     __sock_sendmsg+0x1a6/0x270 net/socket.c:744
     ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2607
     ___sys_sendmsg net/socket.c:2661 [inline]
     __sys_sendmmsg+0x3ab/0x730 net/socket.c:2747
     __do_sys_sendmmsg net/socket.c:2776 [inline]
     __se_sys_sendmmsg net/socket.c:2773 [inline]
     __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2773
     do_syscall_x64 arch/x86/entry/common.c:52 [inline]
     do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
     entry_SYSCALL_64_after_hwframe+0x77/0x7f