CVE-2020-11743

Name	CVE-2020-11743
Description	An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-4723-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
xen (PTS)	jessie, jessie (lts)	4.4.4lts5-0+deb8u1	vulnerable
	stretch (security), stretch (lts), stretch	4.8.5.final+shim4.10.4-1+deb9u12	vulnerable
	buster (security), buster, buster (lts)	4.11.4+107-gef32c7afa2-1	fixed
	bullseye	4.14.6-1	fixed
	bullseye (security)	4.14.5+94-ge49571868d-1	fixed
	bookworm	4.17.3+10-g091466ba55-1~deb12u1	fixed
	sid, trixie	4.17.3+36-g54dacb5c02-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin
xen	source	jessie	(unfixed)	end-of-life
xen	source	stretch	(unfixed)	end-of-life
xen	source	buster	4.11.4+24-gddaaccbbab-1~deb10u1		DSA-4723-1
xen	source	(unstable)	4.11.4-1

[stretch] - xen <end-of-life> (DSA 4602-1)
[jessie] - xen <end-of-life> (Not supported in jessie LTS)
https://xenbits.xen.org/xsa/advisory-316.html