unregister_netdevice: waiting for syz_tun to become free. Usage count = 3
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4051 [inline]
 netdev_hold include/linux/netdevice.h:4080 [inline]
 dst_init+0xda/0x410 net/core/dst.c:52
 dst_alloc+0x12a/0x160 net/core/dst.c:92
 rt_dst_alloc net/ipv4/route.c:1662 [inline]
 __mkroute_output net/ipv4/route.c:2628 [inline]
 ip_route_output_key_hash_rcu+0x14a4/0x23f0 net/ipv4/route.c:2850
 ip_route_output_key_hash+0x1ef/0x330 net/ipv4/route.c:2679
 __ip_route_output_key include/net/route.h:137 [inline]
 ip_route_output_flow+0x26/0x150 net/ipv4/route.c:2909
 ip_route_output_key include/net/route.h:153 [inline]
 geneve_link_config+0x1a2/0x660 drivers/net/geneve.c:1651
 geneve_newlink+0x142/0x1b0 drivers/net/geneve.c:1704
 rtnl_newlink_create net/core/rtnetlink.c:3422 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3642 [inline]
 rtnl_newlink+0x1542/0x2080 net/core/rtnetlink.c:3655
 rtnetlink_rcv_msg+0x87c/0xfc0 net/core/rtnetlink.c:6150
 netlink_rcv_skb+0x1fb/0x450 net/netlink/af_netlink.c:2511
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x497/0x650 net/socket.c:2152
 __do_sys_sendto net/socket.c:2164 [inline]
 __se_sys_sendto net/socket.c:2160 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2160
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4051 [inline]
 netdev_hold include/linux/netdevice.h:4080 [inline]
 fib_check_nh_nongw net/ipv4/fib_semantics.c:1239 [inline]
 fib_check_nh+0xd1f/0x1a70 net/ipv4/fib_semantics.c:1259
 fib_create_info+0x1458/0x2490 net/ipv4/fib_semantics.c:1558
 fib_table_insert+0xc2/0x1b20 net/ipv4/fib_trie.c:1217
 fib_magic+0x2e1/0x3c0 net/ipv4/fib_frontend.c:1118
 fib_add_ifaddr+0x389/0x5e0 net/ipv4/fib_frontend.c:1155
 fib_netdev_event+0x361/0x470 net/ipv4/fib_frontend.c:1500
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455
 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline]
 call_netdevice_notifiers net/core/dev.c:2066 [inline]
 __dev_notify_flags+0x194/0x300 net/core/dev.c:8702
 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8740
 do_setlink+0xba1/0x3e60 net/core/rtnetlink.c:2833
 __rtnl_newlink net/core/rtnetlink.c:3608 [inline]
 rtnl_newlink+0x177c/0x2080 net/core/rtnetlink.c:3655
 rtnetlink_rcv_msg+0x87c/0xfc0 net/core/rtnetlink.c:6150
 netlink_rcv_skb+0x1fb/0x450 net/netlink/af_netlink.c:2511
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x497/0x650 net/socket.c:2152