unregister_netdevice: waiting for syz_tun to become free. Usage count = 2
ref_tracker: netdev@ffff8880425a8658 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4471 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4483 [inline]
     netdev_get_by_index+0x7c/0xb0 net/core/dev.c:1027
     fib6_nh_init+0x657/0x1d80 net/ipv6/route.c:3610
     ip6_route_info_create_nh+0x50b/0xfe0 net/ipv6/route.c:3909
     ip6_route_add+0x80/0x1d0 net/ipv6/route.c:3961
     addrconf_prefix_route+0x2fb/0x510 net/ipv6/addrconf.c:2488
     addrconf_add_linklocal+0x329/0x500 net/ipv6/addrconf.c:3313
     addrconf_addr_gen+0x364/0x3b0 net/ipv6/addrconf.c:3447
     addrconf_dev_config net/ipv6/addrconf.c:3494 [inline]
     addrconf_init_auto_addrs+0x1cb/0x780 net/ipv6/addrconf.c:3572
     addrconf_notify+0x10af/0x1ba0 net/ipv6/addrconf.c:3752
     notifier_call_chain+0x99/0x400 kernel/notifier.c:85
     call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
     call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
     call_netdevice_notifiers net/core/dev.c:2301 [inline]
     __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9794
     netif_change_flags+0x108/0x160 net/core/dev.c:9823
     do_setlink.isra.0+0x1ac4/0x3e60 net/core/rtnetlink.c:3181
     rtnl_changelink net/core/rtnetlink.c:3800 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3973 [inline]
     rtnl_newlink+0x11c2/0x2380 net/core/rtnetlink.c:4110
     rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6996