CVE-2021-47109

Name	CVE-2021-47109
Description	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.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	jessie, jessie (lts)	3.16.84-1	vulnerable
	stretch (security)	4.9.320-2	vulnerable
	stretch (lts), stretch	4.9.320-3	vulnerable
	buster	4.19.249-2	fixed
	buster (security)	4.19.304-1	fixed
	bullseye	5.10.209-2	fixed
	bullseye (security)	5.10.216-1	fixed
	bookworm	6.1.76-1	fixed
	bookworm (security)	6.1.90-1	fixed
	sid, trixie	6.7.12-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency
linux	source	jessie	(unfixed)	end-of-life
linux	source	stretch	(unfixed)	end-of-life
linux	source	buster	(not affected)
linux	source	(unstable)	5.10.46-1

[buster] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/7a6b1ab7475fd6478eeaf5c9d1163e7a18125c8f (5.13-rc7)