CVE-2026-53325

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> agp/amd64: Fix broken error propagation in agp_amd64_probe()<br /> <br /> A NULL pointer dereference was observed in the AMD64 AGP driver when<br /> running in a virtualized environment (e.g. qemu/kvm) without a physical<br /> AMD northbridge. The crash occurs in amd64_fetch_size() when attempting<br /> to dereference the pointer returned by node_to_amd_nb(0).<br /> <br /> The root cause of this crash is broken error propagation in<br /> agp_amd64_probe(): When no AMD northbridges are found, cache_nbs()<br /> correctly returns -ENODEV. However, the probe function erroneously<br /> checks the return value against exactly -1, rather than misc member.<br /> <br /> Fix the issue by correcting the error check in agp_amd64_probe() to<br /> abort properly when cache_nbs() returns any negative error code. This<br /> prevents the driver from erroneously proceeding without hardware, thereby<br /> avoiding the subsequent NULL pointer dereference at its source.