CVE-2026-43035

Name	CVE-2026-43035
Description	In the Linux kernel, the following vulnerability has been resolved: net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to prevent an info-leak When building netlink messages, tc_chain_fill_node() never initializes the tcm_info field of struct tcmsg. Since the allocation is not zeroed, kernel heap memory is leaked to userspace through this 4-byte field. The fix simply zeroes tcm_info alongside the other fields that are already initialized.
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, 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)	5.10.251-5	vulnerable
	bookworm	6.1.170-3	fixed
	bookworm (security)	6.1.172-1	fixed
	trixie	6.12.86-1	fixed
	trixie (security)	6.12.88-1	fixed
	forky, sid	7.0.7-1	fixed
linux-6.1 (PTS)	bullseye (security)	6.1.172-1~deb11u1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	bookworm	6.1.170-1	DSA-6243-1
linux	source	trixie	6.12.85-1
linux	source	(unstable)	6.19.12-1
linux-6.1	source	bullseye	6.1.170-1~deb11u1	DLA-4561-1

https://git.kernel.org/linus/e6e3eb5ee89ac4c163d46429391c889a1bb5e404 (7.0-rc7)