unregister_netdevice: waiting for syz_tun to become free. Usage count = 3
ref_tracker: netdev@ffff88807c554700 has 1/2 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4531 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4543 [inline]
     netdev_get_by_index+0x7c/0xb0 net/core/dev.c:1049
     fib6_nh_init+0x657/0x1d80 net/ipv6/route.c:3621
     ip6_route_info_create_nh+0x50b/0xfe0 net/ipv6/route.c:3920
     addrconf_f6i_alloc+0x312/0x670 net/ipv6/route.c:4727
     fixup_permanent_addr net/ipv6/addrconf.c:3612 [inline]
     addrconf_permanent_addr net/ipv6/addrconf.c:3663 [inline]
     addrconf_notify+0x13c6/0x1ba0 net/ipv6/addrconf.c:3730
     notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85
     call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2275
     call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
     call_netdevice_notifiers net/core/dev.c:2327 [inline]
     __dev_notify_flags+0x22c/0x4b0 net/core/dev.c:9896
     netif_change_flags+0x108/0x160 net/core/dev.c:9925
     do_setlink.isra.0+0x1ac4/0x3e60 net/core/rtnetlink.c:3271
     rtnl_changelink net/core/rtnetlink.c:3910 [inline]
     __rtnl_newlink net/core/rtnetlink.c:4081 [inline]
     rtnl_newlink+0x13c1/0x2620 net/core/rtnetlink.c:4220
     rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:7137
     netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2575
     netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline]
     netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1364
     netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1919
     sock_sendmsg_nosec net/socket.c:800 [inline]
     __sock_sendmsg net/socket.c:815 [inline]
     __sys_sendto+0x48b/0x4e0 net/socket.c:2281

ref_tracker: netdev@ffff88807c554700 has 1/2 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4531 [inline]
     netdev_hold include/linux/netdevice.h:4560 [inline]
     ipv6_add_dev+0x51f/0x1520 net/ipv6/addrconf.c:411
     addrconf_notify+0x5db/0x1ba0 net/ipv6/addrconf.c:3686
     notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85
     call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2275
     call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
     call_netdevice_notifiers net/core/dev.c:2327 [inline]
     register_netdevice+0x1998/0x25a0 net/core/dev.c:11587
     tun_set_iff drivers/net/tun.c:2961 [inline]
     __tun_chr_ioctl+0x1ef4/0x4880 drivers/net/tun.c:3244
     vfs_ioctl fs/ioctl.c:51 [inline]
     __do_sys_ioctl fs/ioctl.c:597 [inline]
     __se_sys_ioctl fs/ioctl.c:583 [inline]
     __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f