Hi,

I'm not subscribed to the Linux netdev mailing list, so I can't
directly reply to the patch email.

This patch is not the correct solution to this issue.

Per RFC 4291 "IP Version 6 Addressing Architecture", all IPv6
interfaces are required to have Link-Local addresses, so therefore
there should always be a link-local address available to use as the
source address for an ND NS.

"2.1. Addressing Model"

...

"All interfaces are required to have at least one Link-Local unicast
   address (see Section 2.8 for additional required addresses)."

I have submitted a more specific bug regarding no Link-Local
address/prefix on the Linux kernel loopback interface through RedHat
bugzilla as I use Fedora 30, however it doesn't seem to have been
looked at yet.

"Loopback network interface does not have a Link Local address,
contrary to RFC 4291"
https://bugzilla.redhat.com/show_bug.cgi?id=1706709


Thanks very much,
Mark.