unregister_netdevice: waiting for syz_tun to become free. Usage count = 4
ref_tracker: syz_tun@ffff8880498f05b8 has 1/3 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline]
     netdev_hold include/linux/netdevice.h:4139 [inline]
     dst_init+0xd9/0x480 net/core/dst.c:52
     dst_alloc+0x12e/0x170 net/core/dst.c:94
     ip6_dst_alloc net/ipv6/route.c:344 [inline]
     ip6_rt_pcpu_alloc net/ipv6/route.c:1420 [inline]
     rt6_make_pcpu_route net/ipv6/route.c:1469 [inline]
     ip6_pol_route+0x94f/0x1230 net/ipv6/route.c:2304
     pol_lookup_func include/net/ip6_fib.h:641 [inline]
     fib6_rule_lookup+0x33d/0x570 net/ipv6/fib6_rules.c:121
     ip6_route_output_flags_noref net/ipv6/route.c:2676 [inline]
     ip6_route_output_flags+0x364/0x5d0 net/ipv6/route.c:2688
     ip6_route_output include/net/ip6_route.h:94 [inline]
     ip6_dst_lookup_tail+0x1ae/0x1530 net/ipv6/ip6_output.c:1133
     ip6_dst_lookup_flow+0x48/0xe0 net/ipv6/ip6_output.c:1264
     rawv6_sendmsg+0xd63/0x1770 net/ipv6/raw.c:892
     sock_sendmsg_nosec net/socket.c:730 [inline]
     __sock_sendmsg net/socket.c:745 [inline]
     ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
     ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
     __sys_sendmsg net/socket.c:2677 [inline]
     __do_sys_sendmsg net/socket.c:2686 [inline]
     __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
     do_syscall_x64 arch/x86/entry/common.c:46 [inline]
     do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
     entry_SYSCALL_64_after_hwframe+0x68/0xd2

ref_tracker: syz_tun@ffff8880498f05b8 has 1/3 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4122 [inline]
     netdev_get_by_index+0x79/0xa0 net/core/dev.c:911
     fib6_nh_init+0x203/0x1ff0 net/ipv6/route.c:3584
     ip6_route_info_create+0x94d/0x1240 net/ipv6/route.c:3854
     ip6_route_add+0x28/0x160 net/ipv6/route.c:3898
     addrconf_prefix_route net/ipv6/addrconf.c:2458 [inline]
     fixup_permanent_addr net/ipv6/addrconf.c:3588 [inline]
     addrconf_permanent_addr+0x6d4/0xa70 net/ipv6/addrconf.c:3612
     addrconf_notify+0x996/0x1010 net/ipv6/addrconf.c:3684
     notifier_call_chain+0x197/0x380 kernel/notifier.c:93
     call_netdevice_notifiers_extack net/core/dev.c:2077 [inline]
     call_netdevice_notifiers net/core/dev.c:2091 [inline]
     __dev_notify_flags+0x1aa/0x310 net/core/dev.c:8762
     dev_change_flags+0xe8/0x1a0 net/core/dev.c:8800
     do_setlink+0xc58/0x4130 net/core/rtnetlink.c:2909
     __rtnl_newlink net/core/rtnetlink.c:3707 [inline]
     rtnl_newlink+0x17da/0x20a0 net/core/rtnetlink.c:3754
     rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6476
     netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
     netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
     netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
     netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
     sock_sendmsg_nosec net/socket.c:730 [inline]
     __sock_sendmsg net/socket.c:745 [inline]
     __sys_sendto+0x4a9/0x6b0 net/socket.c:2200

ref_tracker: syz_tun@ffff8880498f05b8 has 1/3 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline]
     netdev_hold include/linux/netdevice.h:4139 [inline]
     ipv6_add_dev+0x404/0x11e0 net/ipv6/addrconf.c:402
     addrconf_notify+0x67b/0x1010 net/ipv6/addrconf.c:3640
     notifier_call_chain+0x197/0x380 kernel/notifier.c:93
     call_netdevice_notifiers_extack net/core/dev.c:2077 [inline]
     call_netdevice_notifiers net/core/dev.c:2091 [inline]
     register_netdevice+0x16a5/0x1bb0 net/core/dev.c:10351
     tun_set_iff+0x848/0xed0 drivers/net/tun.c:2862
     __tun_chr_ioctl+0x7ee/0x2000 drivers/net/tun.c:3131
     vfs_ioctl fs/ioctl.c:51 [inline]
     __do_sys_ioctl fs/ioctl.c:871 [inline]
     __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
     do_syscall_x64 arch/x86/entry/common.c:46 [inline]
     do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
     entry_SYSCALL_64_after_hwframe+0x68/0xd2