CVE-2021-21781

Name	CVE-2021-21781
Description	An information disclosure vulnerability exists in the ARM SIGPAGE functionality of Linux Kernel v5.4.66 and v5.4.54. The latest version (5.11-rc4) seems to still be vulnerable. A userland application can read the contents of the sigpage, which can leak kernel memory contents. An attacker can read a process’s memory at a specific offset to trigger this vulnerability. This was fixed in kernel releases: 4.14.222 4.19.177 5.4.99 5.10.17 5.11
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-2713-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	buster	4.19.249-2	fixed
	buster (security)	4.19.304-1	fixed
	bullseye	5.10.209-2	fixed
	bullseye (security)	5.10.205-2	fixed
	bookworm	6.1.76-1	fixed
	bookworm (security)	6.1.85-1	fixed
	trixie	6.6.15-2	fixed
	sid	6.7.12-1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	stretch	4.9.272-2	DLA-2713-1
linux	source	buster	4.19.177-1
linux	source	(unstable)	5.10.19-1

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1243
https://git.kernel.org/linus/9c698bff66ab4914bb3d71da7dc6112519bde23e