CVE-2025-21898

Name	CVE-2025-21898
Description	In the Linux kernel, the following vulnerability has been resolved: ftrace: Avoid potential division by zero in function_stat_show() Check whether denominator expression x * (x - 1) * 1000 mod {2^32, 2^64} produce zero and skip stddev computation in that case. For now don't care about rec->counter * rec->counter overflow because rec->time * rec->time overflow will likely happen earlier.
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-4178-1, DLA-4193-1, DSA-5900-1

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)	5.10.244-1	fixed
	bookworm	6.1.148-1	fixed
	bookworm (security)	6.1.158-1	fixed
	trixie	6.12.43-1	fixed
	trixie (security)	6.12.48-1	fixed
	forky	6.16.12-2	fixed
	sid	6.17.7-2	fixed
linux-6.1 (PTS)	bullseye (security)	6.1.153-1~deb11u1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	bullseye	5.10.237-1	DLA-4178-1
linux	source	bookworm	6.1.133-1	DSA-5900-1
linux	source	(unstable)	6.12.19-1
linux-6.1	source	bullseye	6.1.137-1~deb11u1	DLA-4193-1

https://git.kernel.org/linus/a1a7eb89ca0b89dc1c326eeee2596f263291aca3 (6.14-rc5)