CVE-2025-39964

Name	CVE-2025-39964
Description	In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg Issuing two writes to the same af_alg socket is bogus as the data will be interleaved in an unpredictable fashion. Furthermore, concurrent writes may create inconsistencies in the internal socket state. Disallow this by adding a new ctx->write field that indiciates exclusive ownership for writing.
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)

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)	5.10.244-1	vulnerable
	bookworm	6.1.148-1	vulnerable
	bookworm (security)	6.1.153-1	vulnerable
	trixie	6.12.43-1	vulnerable
	trixie (security)	6.12.48-1	vulnerable
	forky	6.16.12-2	fixed
	sid	6.17.6-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
linux	source	(unstable)	6.16.9-1

https://git.kernel.org/linus/1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 (6.17-rc7)