unregister_netdevice: waiting for syz_tun to become free. Usage count = 2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4051 [inline]
 netdev_tracker_alloc include/linux/netdevice.h:4063 [inline]
 fib6_nh_init+0x7f7/0x2190 net/ipv6/route.c:3665
 ip6_route_info_create+0x952/0x1210 net/ipv6/route.c:3846
 ip6_route_add+0x24/0x130 net/ipv6/route.c:3890
 addrconf_prefix_route net/ipv6/addrconf.c:2442 [inline]
 addrconf_add_linklocal+0x449/0x6d0 net/ipv6/addrconf.c:3259
 addrconf_addr_gen+0x55e/0x6a0 net/ipv6/addrconf.c:3388
 addrconf_init_auto_addrs+0x752/0xaf0 net/ipv6/addrconf.c:-1
 addrconf_notify+0xaca/0xf40 net/ipv6/addrconf.c:3685
 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:2039 [inline]
 call_netdevice_notifiers net/core/dev.c:2053 [inline]
 __dev_notify_flags+0x194/0x300 net/core/dev.c:8676
 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8714
 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