CVE-2026-80733

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.