CVE-2025-13350 Use-after-free of orphaned AF_UNIX in Ubuntu builds of Linux kernel

Ubuntu Linux 6.8 GA retains the legacy AFUNIX garbage collector but backports upstream commit 8594d9b85c07 "afunix: Don’t call skbget for OOB skb". When orphaned MSGOOB sockets hit unixgc, the garbage collector still calls kfreeskb as if OOB SKBs held two references; on Ubuntu Linux 6.8 Noble...