unregister_netdevice: waiting for syz_tun to become free. Usage count = 3
ref_tracker: syz_tun@ffff8880263cc5b8 has 1/2 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline]
     netdev_hold include/linux/netdevice.h:4139 [inline]
     dst_init+0xd9/0x460 net/core/dst.c:52
     dst_alloc+0x12e/0x170 net/core/dst.c:93
     rt_dst_alloc net/ipv4/route.c:1662 [inline]
     __mkroute_output net/ipv4/route.c:2626 [inline]
     ip_route_output_key_hash_rcu+0x14f0/0x2360 net/ipv4/route.c:2848
     ip_route_output_key_hash+0x20b/0x340 net/ipv4/route.c:2677
     __ip_route_output_key include/net/route.h:134 [inline]
     ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2905
     ip_route_output_key include/net/route.h:150 [inline]
     geneve_link_config+0x196/0x5f0 drivers/net/geneve.c:1646
     geneve_newlink+0x127/0x180 drivers/net/geneve.c:1699
     rtnl_newlink_create net/core/rtnetlink.c:3517 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3737 [inline]
     rtnl_newlink+0x14d0/0x2020 net/core/rtnetlink.c:3750
     rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6472
     netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
     netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
     netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
     netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
     sock_sendmsg_nosec net/socket.c:730 [inline]
     __sock_sendmsg net/socket.c:745 [inline]
     __sys_sendto+0x46a/0x620 net/socket.c:2201
     __do_sys_sendto net/socket.c:2213 [inline]
     __se_sys_sendto net/socket.c:2209 [inline]
     __x64_sys_sendto+0xde/0xf0 net/socket.c:2209
     do_syscall_x64 arch/x86/entry/common.c:51 [inline]
     do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
     entry_SYSCALL_64_after_hwframe+0x68/0xd2

ref_tracker: syz_tun@ffff8880263cc5b8 has 1/2 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline]
     netdev_hold include/linux/netdevice.h:4139 [inline]
     fib_check_nh_nongw net/ipv4/fib_semantics.c:1239 [inline]
     fib_check_nh+0xc37/0x1900 net/ipv4/fib_semantics.c:1259
     fib_create_info+0x142c/0x2460 net/ipv4/fib_semantics.c:1557
     fib_table_insert+0xc7/0x1b50 net/ipv4/fib_trie.c:1217
     fib_magic+0x2c5/0x390 net/ipv4/fib_frontend.c:1118
     fib_add_ifaddr+0x38d/0x5e0 net/ipv4/fib_frontend.c:1155
     fib_netdev_event+0x389/0x490 net/ipv4/fib_frontend.c:1500
     notifier_call_chain+0x197/0x390 kernel/notifier.c:93
     call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
     call_netdevice_notifiers net/core/dev.c:2078 [inline]
     __dev_notify_flags+0x18e/0x2e0 net/core/dev.c:-1
     dev_change_flags+0xe8/0x1a0 net/core/dev.c:8762
     do_setlink+0xc74/0x3fb0 net/core/rtnetlink.c:2905
     __rtnl_newlink net/core/rtnetlink.c:3703 [inline]
     rtnl_newlink+0x175b/0x2020 net/core/rtnetlink.c:3750
     rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6472
     netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
     netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
     netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
     netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
     sock_sendmsg_nosec net/socket.c:730 [inline]
     __sock_sendmsg net/socket.c:745 [inline]
     __sys_sendto+0x46a/0x620 net/socket.c:2201