Tracker / CVE-2026-53325
CVE-2026-53325
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.
Affected products and versions
| linux | linux_kernel · 2.6.18 → 5.10.260 |
|---|---|
| linux | linux_kernel · 5.11 → 5.15.211 |
| linux | linux_kernel · 5.16 → 6.1.177 |
| linux | linux_kernel · 6.13 → 6.18.37 |
| linux | linux_kernel · 6.19 → 7.0.14 |
| linux | linux_kernel · 6.2 → 6.6.144 |
| linux | linux_kernel · 6.7 → 6.12.95 |
| linux | linux_kernel · 7.1 → 7.1.2 |