unregister_netdevice: waiting for syz_tun to become free. Usage count = 4
ref_tracker: netdev@ffff88805fac47c0 has 1/3 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4499 [inline]
     netdev_hold include/linux/netdevice.h:4528 [inline]
     dst_init+0xbe/0x470 net/core/dst.c:52
     dst_alloc+0x12a/0x170 net/core/dst.c:94
     ip6_dst_alloc net/ipv6/route.c:342 [inline]
     ip6_rt_cache_alloc+0x3ae/0xa10 net/ipv6/route.c:1385
     rt6_do_redirect+0xc2a/0x10d0 net/ipv6/route.c:4345
     ip6_redirect_no_header+0x2a9/0x370 net/ipv6/route.c:3252
     ndisc_redirect_rcv+0x52d/0x950 net/ipv6/ndisc.c:1627
     icmpv6_rcv+0x14d4/0x1f40 net/ipv6/icmp.c:1193
     ip6_protocol_deliver_rcu+0xe8c/0x1680 net/ipv6/ip6_input.c:479
     ip6_input_finish+0x191/0x370 net/ipv6/ip6_input.c:534
     NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
     ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:545
     ip6_mc_input+0x64d/0xbc0 net/ipv6/ip6_input.c:635
     NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
     __netif_receive_skb_one_core net/core/dev.c:6212 [inline]
     __netif_receive_skb net/core/dev.c:6325 [inline]
     netif_receive_skb_internal net/core/dev.c:6411 [inline]
     netif_receive_skb+0x278/0xbf0 net/core/dev.c:6470
     tun_rx_batched+0x1f1/0x760 drivers/net/tun.c:1487
     tun_get_user+0x2b3b/0x4380 drivers/net/tun.c:1955

ref_tracker: netdev@ffff88805fac47c0 has 1/3 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4499 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4511 [inline]
     netdev_get_by_index+0x79/0xb0 net/core/dev.c:1027
     fib6_nh_init+0x285/0x1e40 net/ipv6/route.c:3615
     ip6_route_info_create_nh+0x16a/0xad0 net/ipv6/route.c:3914
     ip6_route_add+0x6e/0x1d0 net/ipv6/route.c:3966
     rt6_add_dflt_router+0x2f3/0x440 net/ipv6/route.c:4501
     ndisc_router_discovery+0x20ef/0x4150 net/ipv6/ndisc.c:1376
     icmpv6_rcv+0x14d4/0x1f40 net/ipv6/icmp.c:1193
     ip6_protocol_deliver_rcu+0xe8c/0x1680 net/ipv6/ip6_input.c:479
     ip6_input_finish+0x191/0x370 net/ipv6/ip6_input.c:534
     NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
     ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:545
     ip6_mc_input+0x64d/0xbc0 net/ipv6/ip6_input.c:635
     NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
     __netif_receive_skb_one_core net/core/dev.c:6212 [inline]
     __netif_receive_skb net/core/dev.c:6325 [inline]
     netif_receive_skb_internal net/core/dev.c:6411 [inline]
     netif_receive_skb+0x278/0xbf0 net/core/dev.c:6470
     tun_rx_batched+0x1f1/0x760 drivers/net/tun.c:1487
     tun_get_user+0x2b3b/0x4380 drivers/net/tun.c:1955

ref_tracker: netdev@ffff88805fac47c0 has 1/3 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4499 [inline]
     netdev_hold include/linux/netdevice.h:4528 [inline]
     ipv6_add_dev+0x54d/0x1400 net/ipv6/addrconf.c:411
     addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3685
     notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
     call_netdevice_notifiers_extack net/core/dev.c:2288 [inline]
     call_netdevice_notifiers net/core/dev.c:2302 [inline]
     register_netdevice+0x18c0/0x1ed0 net/core/dev.c:11484
     tun_set_iff+0x817/0xec0 drivers/net/tun.c:2813
     __tun_chr_ioctl+0x7be/0x1e10 drivers/net/tun.c:3094
     vfs_ioctl fs/ioctl.c:51 [inline]
     __do_sys_ioctl fs/ioctl.c:597 [inline]
     __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
     do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
     do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
     entry_SYSCALL_64_after_hwframe+0x77/0x7f