unregister_netdevice: waiting for netdevsim1 to become free. Usage count = 2
ref_tracker: netdev@0000000064afe77d has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4412 [inline]
     netdev_get_by_index+0x88/0xe4 net/core/dev.c:1008
     fib6_nh_init+0x198/0x1960 net/ipv6/route.c:3601
     ip6_route_info_create_nh+0x11c/0x98c net/ipv6/route.c:3901
     addrconf_f6i_alloc+0x1c4/0x378 net/ipv6/route.c:4693
     ipv6_add_addr+0x458/0xdb8 net/ipv6/addrconf.c:1126
     addrconf_add_linklocal+0x230/0x5d4 net/ipv6/addrconf.c:3311
     addrconf_addr_gen+0x38c/0x464 net/ipv6/addrconf.c:3442
     addrconf_init_auto_addrs+0x488/0x8cc net/ipv6/addrconf.c:-1
     addrconf_notify+0x8ac/0xd14 net/ipv6/addrconf.c:3740
     notifier_call_chain+0x190/0x4cc kernel/notifier.c:85
     raw_notifier_call_chain+0x3c/0x50 kernel/notifier.c:453
     call_netdevice_notifiers_info net/core/dev.c:2230 [inline]
     call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
     call_netdevice_notifiers net/core/dev.c:2282 [inline]
     __dev_notify_flags+0x218/0x464 net/core/dev.c:-1
     netif_change_flags+0xd0/0x15c net/core/dev.c:9804
     do_setlink+0xa58/0x3658 net/core/rtnetlink.c:3158
     rtnl_changelink net/core/rtnetlink.c:3776 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3935 [inline]
     rtnl_newlink+0x1104/0x15e8 net/core/rtnetlink.c:4072
     rtnetlink_rcv_msg+0x664/0x97c net/core/rtnetlink.c:6958