CVE-2026-53325

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

agp/amd64: Fix broken error propagation in agp_amd64_probe()

A NULL pointer dereference was observed in the AMD64 AGP driver when

running in a virtualized environment (e.g. qemu/kvm) without a physical

AMD northbridge. The crash occurs in amd64_fetch_size() when attempting

to dereference the pointer returned by node_to_amd_nb(0).

The root cause of this crash is broken error propagation in

agp_amd64_probe(): When no AMD northbridges are found, cache_nbs()

correctly returns -ENODEV. However, the probe function erroneously

checks the return value against exactly -1, rather than < 0.

As a result, the hardware absence error is masked, allowing the driver

to improperly proceed with initialization. It eventually calls

agp_add_bridge(), which invokes amd64_fetch_size(). Since the hardware

does not exist, node_to_amd_nb(0) returns NULL, leading to a General

Protection Fault (GPF) when accessing its ->misc member.

Fix the i

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References