unregister_netdevice: waiting for syz_tun to become free. Usage count = 2
ref_tracker: netdev@ffff888044028620 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4435 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4447 [inline]
     netdev_get_by_index+0x79/0xb0 net/core/dev.c:1027
     fib6_nh_init+0x202/0x1f90 net/ipv6/route.c:3600
     ip6_route_info_create_nh+0x16a/0xad0 net/ipv6/route.c:3899
     ip6_route_add+0x6e/0x1b0 net/ipv6/route.c:3951
     addrconf_prefix_route+0x3a2/0x480 net/ipv6/addrconf.c:2487
     fixup_permanent_addr net/ipv6/addrconf.c:3602 [inline]
     addrconf_permanent_addr+0x454/0x740 net/ipv6/addrconf.c:3626
     addrconf_notify+0x864/0x1050 net/ipv6/addrconf.c:3698
     notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
     call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
     call_netdevice_notifiers net/core/dev.c:2301 [inline]
     __dev_notify_flags+0x1a9/0x310 net/core/dev.c:9803
     netif_change_flags+0xe8/0x1a0 net/core/dev.c:9832
     do_setlink+0xf82/0x4590 net/core/rtnetlink.c:3158
     rtnl_changelink net/core/rtnetlink.c:3776 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3935 [inline]
     rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink.c:4072
     rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958
     netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
     netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
     netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
     netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894