Linux Auditd SOCK RAW EAFNOSUPPORT From User Writable Path

The following analytic detects a process executing from a user-writable directory calling socket() with SOCK_RAW (a1=3) and receiving EAFNOSUPPORT (exit=-97, errno 97). This is the kernel trigger for vhost-vsock class privilege escalation exploits. When socket() is called with an unregistered address family and SOCK_RAW, the kernel calls request_module() to attempt to load a matching protocol module. In vulnerable kernels, this triggers a stale IOTLB metadata cache access path that allows an unprivileged user to write an arbitrary value to modprobe_path. The specific address family number varies by kernel and exploit variant (AF 41, 42, or any unregistered AF).