PT-2026-53209 · Linux · Linux
Published
2026-06-29
·
Updated
2026-06-29
·
CVE-2026-53325
None
No severity ratings or metrics are available. When they are, we'll update the corresponding info on the page.
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 issue by correcting the error check in agp amd64 probe() to
abort properly when cache nbs() returns any negative error code. This
prevents the driver from erroneously proceeding without hardware, thereby
avoiding the subsequent NULL pointer dereference at its source.
Found an issue in the description? Have something to add? Feel free to write us 👾
Related Identifiers
Affected Products
Linux