unregister_netdevice: waiting for syz_tun to become free. Usage count = 2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4070 [inline]
 netdev_tracker_alloc include/linux/netdevice.h:4082 [inline]
 fib6_nh_init+0x664/0x1c84 net/ipv6/route.c:3613
 ip6_route_info_create+0x7ac/0xf14 net/ipv6/route.c:3791
 ip6_route_add+0x38/0x168 net/ipv6/route.c:3835
 addrconf_add_mroute net/ipv6/addrconf.c:2489 [inline]
 addrconf_add_dev+0x2b8/0x458 net/ipv6/addrconf.c:2507
 addrconf_dev_config net/ipv6/addrconf.c:3382 [inline]
 addrconf_init_auto_addrs+0x708/0xc9c net/ipv6/addrconf.c:3469
 addrconf_notify+0x7e8/0xcb4 net/ipv6/addrconf.c:3642
 notifier_call_chain+0x1a4/0x510 kernel/notifier.c:93
 raw_notifier_call_chain+0x3c/0x50 kernel/notifier.c:461
 __dev_notify_flags+0x2bc/0x544
 dev_change_flags+0xd0/0x15c net/core/dev.c:8643
 do_setlink+0xc3c/0x23d4 net/core/rtnetlink.c:2836
 __rtnl_newlink net/core/rtnetlink.c:3626 [inline]
 rtnl_newlink+0x1354/0x1b1c net/core/rtnetlink.c:3673
 rtnetlink_rcv_msg+0x744/0xdb8 net/core/rtnetlink.c:6395
 netlink_rcv_skb+0x214/0x3c4 net/netlink/af_netlink.c:2546
 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6413
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1365