CVE-2025-40011: 
Linux Kernel vulnerability analysis and mitigation

A vulnerability has been identified in the Linux kernel affecting the drm/gma500 component, tracked as CVE-2025-40011. The vulnerability was discovered by the Linux Verification Center (linuxtesting.org) with Svacer and was disclosed on October 20, 2025. The issue affects various Linux distributions including Red Hat Enterprise Linux versions 6 through 10 (NVD, Debian Tracker).

The vulnerability involves a null pointer dereference in the HDMI teardown process within the GMA500 graphics driver. Specifically, pcisetdrvdata sets the value of pdev->driverdata to NULL, after which the driverdata obtained from the same device is dereferenced in oaktrailhdmii2cexit, where the i2cdev is extracted from it. The issue has been assigned a CVSS v3 score of 7.0, indicating moderate severity (Red Hat Security).

The vulnerability could lead to system instability or crashes when the HDMI functionality is being torn down in systems using the GMA500 graphics driver. This affects multiple Linux distributions, with the vulnerability being marked as 'vulnerable' in various releases including bullseye, bookworm, trixie, and forky, while being fixed in the sid release (Debian Tracker).

A fix has been implemented that involves reordering the calls to prevent the null pointer dereference. The issue has been resolved in the sid release, while other versions are being updated. System administrators are advised to update their systems once patches are available for their respective distributions (Debian Tracker).