CVE-2022-48979 is a vulnerability identified in the Linux kernel specifically within the Direct Rendering Manager (DRM) subsystem for AMD graphics, in the display driver code related to DCN32 DML (Display Core Next generation 32 Display Mode Library). The issue arises from an array index out-of-bounds error in the handling of the LinkCapacitySupport array. The vulnerability is caused because the array is indexed using the number of voltage states rather than the number of maximum Display Pipe Processors (DPPs), which leads to accessing memory beyond the allocated array bounds. This kind of programming error can result in undefined behavior, including potential memory corruption, crashes, or other erratic behavior in the kernel space. The fix involved correcting the array declaration to match the correct size, which is the total number of voltage states, thereby preventing out-of-bounds access. This vulnerability affects Linux kernel versions identified by the commit hash 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and likely other versions containing the same flawed code. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The vulnerability is technical and low-level, affecting the AMD display driver component within the Linux kernel, which is critical for graphical output and display management on systems using AMD GPUs with Linux.

For European organizations, the impact of CVE-2022-48979 depends largely on the deployment of Linux systems running AMD GPUs with the affected kernel versions. If exploited, the out-of-bounds array access could lead to kernel crashes (denial of service), potential privilege escalation, or arbitrary code execution in kernel space, which could compromise system integrity and availability. This is particularly concerning for organizations relying on Linux servers or workstations with AMD graphics for critical operations, such as media production, scientific computing, or any graphical workloads. The vulnerability could also be leveraged as a foothold in multi-tenant environments or cloud infrastructures where Linux AMD GPU-enabled instances are used. However, since no known exploits exist yet, the immediate risk is moderate but could increase if exploit code is developed. Confidentiality impact is limited unless combined with other vulnerabilities, but integrity and availability impacts are significant due to kernel-level exploitation potential.

European organizations should prioritize updating their Linux kernels to versions where this vulnerability is patched. Since the fix involves correcting the array size in the AMD DRM driver, applying the latest stable kernel releases or vendor-provided patches that include this fix is essential. Organizations using custom or long-term support kernels should backport the patch if possible. Additionally, system administrators should audit systems with AMD GPUs to identify affected kernel versions and GPU drivers. Employing kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), Kernel Page Table Isolation (KPTI), and enabling security modules like SELinux or AppArmor can reduce exploitation likelihood. Monitoring system logs for unusual GPU driver crashes or kernel oops messages may help detect attempted exploitation. Finally, restricting access to systems with AMD GPUs and limiting user privileges can reduce the attack surface.