unregister_netdevice: waiting for netdevsim2 to become free. Usage count = 2
ref_tracker: eth%d@00000000216dc6a8 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4331 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4343 [inline]
     netdev_get_by_index+0x88/0xe4 net/core/dev.c:1006
     fib6_nh_init+0x198/0x1960 net/ipv6/route.c:3583
     ip6_route_info_create+0x78c/0xf5c net/ipv6/route.c:3852
     addrconf_f6i_alloc+0x194/0x33c net/ipv6/route.c:4631
     ipv6_add_addr+0x458/0xdb8 net/ipv6/addrconf.c:1121
     addrconf_add_linklocal+0x230/0x5d4 net/ipv6/addrconf.c:3313
     addrconf_addr_gen+0x38c/0x464 net/ipv6/addrconf.c:3444
     addrconf_init_auto_addrs+0x624/0x9ac net/ipv6/addrconf.c:-1
     addrconf_notify+0x8cc/0xcdc net/ipv6/addrconf.c:3741
     notifier_call_chain+0x1b8/0x4e4 kernel/notifier.c:85
     raw_notifier_call_chain+0x3c/0x50 kernel/notifier.c:453
     call_netdevice_notifiers_info net/core/dev.c:2176 [inline]
     call_netdevice_notifiers_extack net/core/dev.c:2214 [inline]
     call_netdevice_notifiers net/core/dev.c:2228 [inline]
     __dev_notify_flags+0x260/0x47c net/core/dev.c:-1
     netif_change_flags+0xd0/0x15c net/core/dev.c:9434
     do_setlink+0xaa8/0x3860 net/core/rtnetlink.c:3152
     rtnl_changelink net/core/rtnetlink.c:3769 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3928 [inline]
     rtnl_newlink+0x10f8/0x15dc net/core/rtnetlink.c:4065
     rtnetlink_rcv_msg+0x664/0x97c net/core/rtnetlink.c:6955