Linux Kernel HDMI Audio Callback Null Pointer Dereference Vulnerability

A vulnerability in the Linux kernel's HDMI audio handling can lead to a null pointer dereference. When a driver is removed, the HDMI codec's removal function calls a callback with a null function pointer, causing a kernel Oops error. The vulnerability arises because the callback is executed without checking if the function pointer is non-null. The issue has been fixed by ensuring the callback is only called if the function pointer is valid, allowing the callback members to be properly cleared.

Impact

Exploitation of this vulnerability leads to a null pointer dereference, causing a kernel Oops error, which can potentially be exploited to escalate privileges or cause a denial-of-service condition by crashing the system.