unregister_netdevice: waiting for syz_tun to become free. Usage count = 2453
ref_tracker: syz_tun@ffff88802004c610 has 491/2452 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4341 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4353 [inline]
     netdev_get_by_index+0x7c/0xb0 net/core/dev.c:1008
     fib6_nh_init+0x791/0x1fb0 net/ipv6/route.c:3592
     ip6_route_info_create_nh+0x507/0xfa0 net/ipv6/route.c:3845
     addrconf_f6i_alloc+0x313/0x660 net/ipv6/route.c:4683
     ipv6_add_addr+0x531/0x1fe0 net/ipv6/addrconf.c:1121
     addrconf_add_linklocal+0x2a5/0x500 net/ipv6/addrconf.c:3310
     addrconf_addr_gen+0x36d/0x3c0 net/ipv6/addrconf.c:3441
     addrconf_dev_config net/ipv6/addrconf.c:3487 [inline]
     addrconf_init_auto_addrs+0x4b9/0x8f0 net/ipv6/addrconf.c:3571
     addrconf_notify+0xe93/0x19e0 net/ipv6/addrconf.c:3744
     notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
     call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
     call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
     call_netdevice_notifiers net/core/dev.c:2282 [inline]
     __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9497
     netif_change_flags+0x108/0x160 net/core/dev.c:9526
     do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3141
     rtnl_group_changelink net/core/rtnetlink.c:3773 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3927 [inline]
     rtnl_newlink+0x18e0/0x2000 net/core/rtnetlink.c:4055
     rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944

ref_tracker: syz_tun@ffff88802004c610 has 490/2452 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4341 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4353 [inline]
     netdev_get_by_index+0x7c/0xb0 net/core/dev.c:1008
     fib6_nh_init+0x791/0x1fb0 net/ipv6/route.c:3592
     ip6_route_info_create_nh+0x507/0xfa0 net/ipv6/route.c:3845
     ip6_route_add+0x5a/0x1d0 net/ipv6/route.c:3893
     addrconf_prefix_route+0x2fd/0x510 net/ipv6/addrconf.c:2487
     addrconf_add_linklocal+0x329/0x500 net/ipv6/addrconf.c:3312
     addrconf_addr_gen+0x36d/0x3c0 net/ipv6/addrconf.c:3441
     addrconf_dev_config net/ipv6/addrconf.c:3487 [inline]
     addrconf_init_auto_addrs+0x4b9/0x8f0 net/ipv6/addrconf.c:3571
     addrconf_notify+0xe93/0x19e0 net/ipv6/addrconf.c:3744
     notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
     call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
     call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
     call_netdevice_notifiers net/core/dev.c:2282 [inline]
     __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9497
     netif_change_flags+0x108/0x160 net/core/dev.c:9526
     do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3141
     rtnl_group_changelink net/core/rtnetlink.c:3773 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3927 [inline]
     rtnl_newlink+0x18e0/0x2000 net/core/rtnetlink.c:4055
     rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944

ref_tracker: syz_tun@ffff88802004c610 has 490/2452 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4341 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4353 [inline]
     netdev_get_by_index+0x7c/0xb0 net/core/dev.c:1008
     fib6_nh_init+0x791/0x1fb0 net/ipv6/route.c:3592
     ip6_route_info_create_nh+0x507/0xfa0 net/ipv6/route.c:3845
     ip6_route_add+0x5a/0x1d0 net/ipv6/route.c:3893
     addrconf_add_mroute+0x1dd/0x350 net/ipv6/addrconf.c:2551
     addrconf_add_dev+0x14e/0x1c0 net/ipv6/addrconf.c:2569
     addrconf_dev_config net/ipv6/addrconf.c:3477 [inline]
     addrconf_init_auto_addrs+0x3f3/0x8f0 net/ipv6/addrconf.c:3571
     addrconf_notify+0xe93/0x19e0 net/ipv6/addrconf.c:3744
     notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
     call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
     call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
     call_netdevice_notifiers net/core/dev.c:2282 [inline]
     __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9497
     netif_change_flags+0x108/0x160 net/core/dev.c:9526
     do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3141
     rtnl_group_changelink net/core/rtnetlink.c:3773 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3927 [inline]
     rtnl_newlink+0x18e0/0x2000 net/core/rtnetlink.c:4055
     rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944
     netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534

ref_tracker: syz_tun@ffff88802004c610 has 490/2452 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4341 [inline]
     netdev_hold include/linux/netdevice.h:4370 [inline]
     netdev_hold include/linux/netdevice.h:4365 [inline]
     fib_check_nh_nongw net/ipv4/fib_semantics.c:1268 [inline]
     fib_check_nh+0x271/0x620 net/ipv4/fib_semantics.c:1288
     fib_create_info+0x21de/0x46b0 net/ipv4/fib_semantics.c:1508
     fib_table_insert+0x177/0x1c40 net/ipv4/fib_trie.c:1212
     fib_magic+0x4d4/0x5c0 net/ipv4/fib_frontend.c:1133
     fib_add_ifaddr+0x4d2/0x580 net/ipv4/fib_frontend.c:1177
     fib_netdev_event+0x38a/0x710 net/ipv4/fib_frontend.c:1515
     notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
     call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
     call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
     call_netdevice_notifiers net/core/dev.c:2282 [inline]
     __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9497
     netif_change_flags+0x108/0x160 net/core/dev.c:9526
     do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3141
     rtnl_group_changelink net/core/rtnetlink.c:3773 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3927 [inline]
     rtnl_newlink+0x18e0/0x2000 net/core/rtnetlink.c:4055
     rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944
     netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534
     netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
     netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
     netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883

ref_tracker: syz_tun@ffff88802004c610 has 490/2452 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4341 [inline]
     netdev_hold include/linux/netdevice.h:4370 [inline]
     netdev_hold include/linux/netdevice.h:4365 [inline]
     fib_check_nh_nongw net/ipv4/fib_semantics.c:1268 [inline]
     fib_check_nh+0x271/0x620 net/ipv4/fib_semantics.c:1288
     fib_create_info+0x21de/0x46b0 net/ipv4/fib_semantics.c:1508
     fib_table_insert+0x177/0x1c40 net/ipv4/fib_trie.c:1212
     fib_magic+0x4d4/0x5c0 net/ipv4/fib_frontend.c:1133
     fib_add_ifaddr+0x3a1/0x580 net/ipv4/fib_frontend.c:1170
     fib_netdev_event+0x38a/0x710 net/ipv4/fib_frontend.c:1515
     notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
     call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
     call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
     call_netdevice_notifiers net/core/dev.c:2282 [inline]
     __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9497
     netif_change_flags+0x108/0x160 net/core/dev.c:9526
     do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3141
     rtnl_group_changelink net/core/rtnetlink.c:3773 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3927 [inline]
     rtnl_newlink+0x18e0/0x2000 net/core/rtnetlink.c:4055
     rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944
     netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534
     netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
     netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
     netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883

ref_tracker: syz_tun@ffff88802004c610 has 1/2452 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4341 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4353 [inline]
     fib_create_info+0x2b74/0x46b0 net/ipv4/fib_semantics.c:1502
     fib_table_insert+0x177/0x1c40 net/ipv4/fib_trie.c:1212
     fib_magic+0x4d4/0x5c0 net/ipv4/fib_frontend.c:1133
     fib_add_ifaddr+0x16d/0x580 net/ipv4/fib_frontend.c:1155
     fib_inetaddr_event+0x147/0x270 net/ipv4/fib_frontend.c:1469
     notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
     blocking_notifier_call_chain kernel/notifier.c:380 [inline]
     blocking_notifier_call_chain+0x69/0xa0 kernel/notifier.c:368
     __inet_insert_ifa+0x925/0xcd0 net/ipv4/devinet.c:567
     inet_rtm_newaddr+0xd87/0x1540 net/ipv4/devinet.c:1002
     rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944
     netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534
     netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
     netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
     netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
     sock_sendmsg_nosec net/socket.c:712 [inline]
     __sock_sendmsg net/socket.c:727 [inline]
     __sys_sendto+0x4a0/0x520 net/socket.c:2180
     __do_sys_sendto net/socket.c:2187 [inline]
     __se_sys_sendto net/socket.c:2183 [inline]
     __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2183
     do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
     do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94