Linux Kernel NULL Pointer Dereference Vulnerability in Intel DMC Management

A vulnerability in the Linux kernel's handling of Intel Display Management Command (DMC) can lead to a NULL pointer dereference. This issue occurs in the graphics driver when the DMC has not been properly initialized, causing a crash. The vulnerability arises during the display power management initialization process, where the driver incorrectly assumes that certain power states are available. This flaw is particularly related to the management of 'DC6' power states, which can be unintentionally left enabled by the system's BIOS without the necessary firmware being loaded, creating a rare but critical failure condition.

Impact

Exploitation of this vulnerability causes a system crash due to a NULL pointer dereference, disrupting normal operations and potentially leading to a denial of service.

Reproduction

The vulnerability can be reproduced by initializing the display power management before the DMC firmware is loaded by the BIOS. This sequence can leave the DC6 power state enabled without the required firmware, causing a crash when the driver attempts to update the DC6 state management.

Remediation

Users can apply the latest patches available in the Linux kernel stable tree to address this vulnerability.