CVE-2026-31671

Name	CVE-2026-31671
Description	In the Linux kernel, the following vulnerability has been resolved: xfrm_user: fix info leak in build_report() struct xfrm_user_report is a __u8 proto field followed by a struct xfrm_selector which means there is three "empty" bytes of padding, but the padding is never zeroed before copying to userspace. Fix that up by zeroing the structure before setting individual member variables.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-4561-1, DLA-4606-1, DSA-6238-1, DSA-6243-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	vulnerable
	bullseye (security)	5.10.257-1	fixed
	bookworm	6.1.170-3	fixed
	bookworm (security)	6.1.174-1	fixed
	trixie	6.12.86-1	fixed
	trixie (security)	6.12.90-2	fixed
	forky, sid	7.0.10-1	fixed
linux-6.1 (PTS)	bullseye (security)	6.1.174-1~deb11u1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	bullseye	5.10.257-1	DLA-4606-1
linux	source	bookworm	6.1.170-1	DSA-6243-1
linux	source	trixie	6.12.85-1	DSA-6238-1
linux	source	(unstable)	6.19.13-1
linux-6.1	source	bullseye	6.1.170-1~deb11u1	DLA-4561-1

https://git.kernel.org/linus/d10119968d0e1f2b669604baf2a8b5fdb72fa6b4 (7.0)