unregister_netdevice: waiting for lo to become free. Usage count = 1025
ref_tracker: lo@ffff888021fca608 has 1024/1024 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4136 [inline]
     netdev_hold include/linux/netdevice.h:4165 [inline]
     dst_init+0xda/0x580 net/core/dst.c:52
     dst_alloc+0xbb/0x1a0 net/core/dst.c:93
     rt_dst_clone+0x5a/0x860 net/ipv4/route.c:1653
     ip_mc_finish_output+0xaf/0x680 net/ipv4/ip_output.c:356
     NF_HOOK include/linux/netfilter.h:314 [inline]
     NF_HOOK include/linux/netfilter.h:308 [inline]
     ip_mc_output+0x5e1/0x6a0 net/ipv4/ip_output.c:400
     dst_output include/net/dst.h:450 [inline]
     dst_output include/net/dst.h:448 [inline]
     ip_local_out net/ipv4/ip_output.c:130 [inline]
     ip_send_skb+0x326/0x560 net/ipv4/ip_output.c:1505
     udp_send_skb+0x6f1/0x1510 net/ipv4/udp.c:1142
     udp_sendmsg+0x1899/0x29b0 net/ipv4/udp.c:1430
     inet_sendmsg+0x105/0x140 net/ipv4/af_inet.c:851
     sock_sendmsg_nosec net/socket.c:711 [inline]
     __sock_sendmsg net/socket.c:726 [inline]
     ____sys_sendmsg+0x907/0xb40 net/socket.c:2583
     ___sys_sendmsg+0x135/0x1e0 net/socket.c:2637
     __sys_sendmmsg+0x2fa/0x420 net/socket.c:2719
     __compat_sys_sendmmsg net/compat.c:360 [inline]
     __do_compat_sys_sendmmsg net/compat.c:367 [inline]
     __se_compat_sys_sendmmsg net/compat.c:364 [inline]
     __ia32_compat_sys_sendmmsg+0x9d/0x100 net/compat.c:364
     do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
     __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
     do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
     entry_SYSENTER_compat_after_hwframe+0x84/0x8e