unregister_netdevice: waiting for C to become free. Usage count = 2
ref_tracker: netdev@ffff888112200700 has 1/1 users at
     dst_init+0xbe/0x470
     dst_alloc+0x12a/0x170
     rt_dst_clone+0x52/0x680
     ip_mc_finish_output+0xea/0x2e0
     ip_mc_output+0x254/0x580
     ip_send_skb+0x45/0xc0
     udp_send_skb+0x7f7/0xfb0
     udp_sendmsg+0x1971/0x2140
     udpv6_sendmsg+0x915/0x2610
     sock_sendmsg_nosec+0x90/0x180
     sock_write_iter+0x2de/0x3e0
     vfs_write+0x612/0xba0
     ksys_write+0x150/0x270
     do_syscall_64+0x174/0x580
     entry_SYSCALL_64_after_hwframe+0x77/0x7f

