CVE-2026-68123

Name	CVE-2026-68123
Description	In the Linux kernel, the following vulnerability has been resolved: openvswitch: fix GSO userspace truncation underflow OVS_ACTION_ATTR_TRUNC currently stores a delta from the original skb length in OVS_CB(skb)->cutlen. When a later userspace action segments a GSO skb, queue_gso_packets() reuses that delta for each smaller segment. A segment can then reach queue_userspace_packet() with cutlen greater than skb->len, underflowing the length passed to skb_zerocopy(). Store the maximum preserved length instead and bound each consumer against the current skb length. Use U32_MAX as the no-truncation sentinel so the value remains valid if skb geometry changes before a consumer handles it.
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-4745-1

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)	5.10.262-1	vulnerable
	bookworm	6.1.176-1	vulnerable
	bookworm (security)	6.1.180-1	vulnerable
	trixie	6.12.94-1	vulnerable
	trixie (security)	6.12.107-1	fixed
	forky	7.1.8-2	fixed
	sid	7.1.12-1	fixed
linux-6.12 (PTS)	bookworm (security)	6.12.101-1~deb12u1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	trixie	6.12.101-1
linux	source	(unstable)	7.1.6-1
linux-6.12	source	bookworm	6.12.101-1~deb12u1	DLA-4745-1

https://git.kernel.org/linus/4032f8ed10fcb84d41c508dfb04be96589f78dfe (7.2-rc5)