CVE-2026-80733

Name	CVE-2026-80733
Description	In the Linux kernel, the following vulnerability has been resolved: net: remove WARN_ON_ONCE() from sk_mc_loop() sk_mc_loop() can be called for sockets that are neither AF_INET nor AF_INET6 (e.g. AF_PACKET sockets when sending packets via raw/packet socket over virtual devices such as VRF or ipvlan). In such cases, sk_family is not AF_INET/AF_INET6 and sk_mc_loop() falls through the switch statement and triggers WARN_ON_ONCE(1). Non-INET sockets do not support IP_MULTICAST_LOOP or IPV6_MULTICAST_LOOP options, so loopback should default to true without generating a warning.
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-4777-1, DLA-4788-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bookworm	6.1.176-1	vulnerable
	bookworm (security)	6.1.187-1	fixed
	trixie (security), trixie	6.12.107-1	fixed
	forky	7.2.6-1	fixed
	sid	7.2.7-1	fixed
linux-6.12 (PTS)	bookworm (security)	6.12.107-1~deb12u1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	bookworm	6.1.187-1	DLA-4777-1
linux	source	trixie	6.12.105-1
linux	source	(unstable)	7.1.9-1
linux-6.12	source	bookworm	6.12.107-1~deb12u1	DLA-4788-1

https://git.kernel.org/linus/b8a39a09ae4eaae04309e1e38ed6a1101d967496 (7.2-rc7)