CVE-2021-47109

In the Linux kernel, the following vulnerability has been resolved:

neighbour: allow NUD_NOARP entries to be forced GCed

IFF_POINTOPOINT interfaces use NUD_NOARP entries for IPv6. It's possible to

fill up the neighbour table with enough entries that it will overflow for

valid connections after that.

This behaviour is more prevalent after commit 58956317c8de ("neighbor:

Improve garbage collection") is applied, as it prevents removal from

entries that are not NUD_FAILED, unless they are more than 5s old.