unregister_netdevice: waiting for syz_tun to become free. Usage count = 3
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4046 [inline]
 netdev_tracker_alloc include/linux/netdevice.h:4058 [inline]
 fib6_nh_init+0x7ba/0x1fc0 net/ipv6/route.c:3667
 ip6_route_info_create+0x971/0x1220 net/ipv6/route.c:3848
 addrconf_f6i_alloc+0x1ec/0x430 net/ipv6/route.c:4623
 fixup_permanent_addr net/ipv6/addrconf.c:3535 [inline]
 addrconf_permanent_addr+0x2a6/0xa30 net/ipv6/addrconf.c:3574
 addrconf_notify+0x988/0xf60 net/ipv6/addrconf.c:3646
 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:2052 [inline]
 call_netdevice_notifiers net/core/dev.c:2066 [inline]
 __dev_notify_flags+0x1a7/0x310 net/core/dev.c:8715
 dev_change_flags+0xda/0x1a0 net/core/dev.c:8753
 do_setlink+0xbc7/0x29c0 net/core/rtnetlink.c:2845
 __rtnl_newlink net/core/rtnetlink.c:3622 [inline]
 rtnl_newlink+0x16e4/0x1f90 net/core/rtnetlink.c:3669
 rtnetlink_rcv_msg+0x863/0xfb0 net/core/rtnetlink.c:6166
 netlink_rcv_skb+0x1ef/0x440 net/netlink/af_netlink.c:2516
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x7ad/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1877
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x497/0x650 net/socket.c:2153
 __do_sys_sendto net/socket.c:2165 [inline]
 __se_sys_sendto net/socket.c:2161 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2161
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4046 [inline]
 netdev_hold include/linux/netdevice.h:4075 [inline]
 ipv6_add_dev+0x3e8/0x1110 net/ipv6/addrconf.c:402
 addrconf_notify+0x634/0xf60 net/ipv6/addrconf.c:3602
 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:2052 [inline]
 call_netdevice_notifiers net/core/dev.c:2066 [inline]
 register_netdevice+0x16a8/0x1b80 net/core/dev.c:10276
 tun_set_iff+0x82b/0xea0 drivers/net/tun.c:2865
 __tun_chr_ioctl+0x770/0x1ed0 drivers/net/tun.c:3128
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2