CVE-2024-26662 is a medium-severity vulnerability identified in the Linux kernel's AMD GPU driver, specifically within the Direct Rendering Manager (DRM) subsystem responsible for managing AMD display hardware. The flaw arises in the function dcn21_set_backlight_level(), which is part of the display controller hardware sequence implementation for the DCN2.1 (Display Core Next) architecture. The vulnerability is due to a null pointer dereference caused by the 'panel_cntl' structure being potentially null when accessed. This structure controls the display panel, and the code previously assumed it was always valid, leading to an unsafe dereference. When 'panel_cntl' is null, dereferencing it results in a kernel null pointer access, which can cause a denial of service (DoS) by crashing the kernel or triggering a system panic. The vulnerability requires local privileges (low attack complexity and privileges required) but does not require user interaction. The CVSS v3.1 base score is 5.5, reflecting a medium severity primarily due to the impact on availability (system crash) without affecting confidentiality or integrity. No known exploits are reported in the wild as of the publication date. The issue has been fixed in the Linux kernel source code by adding proper null checks or handling to prevent dereferencing a null 'panel_cntl' pointer. This vulnerability affects Linux kernel versions containing the specified commit hashes prior to the fix. Since the flaw is in the AMD GPU driver, systems using AMD graphics hardware on Linux are impacted, particularly those running affected kernel versions with the DCN2.1 display controller implementation. This includes many desktop and server Linux distributions that support AMD GPUs. The vulnerability does not allow privilege escalation or code execution but can cause system instability or crashes, which may disrupt operations or services relying on affected Linux systems.

For European organizations, the primary impact of CVE-2024-26662 is potential denial of service on Linux systems equipped with AMD GPUs running affected kernel versions. This could lead to unexpected system crashes or reboots, causing downtime for critical infrastructure, workstations, or servers. Industries relying on Linux-based systems with AMD graphics for graphical processing, visualization, or compute tasks—such as media production, scientific research, and certain enterprise environments—may experience operational disruptions. Although the vulnerability does not compromise data confidentiality or integrity, availability interruptions can affect business continuity, especially in environments with limited redundancy or where rapid recovery is challenging. The requirement for local privileges limits remote exploitation, but insider threats or compromised user accounts could trigger the issue. European organizations with strict uptime requirements or those operating in sectors like finance, healthcare, or manufacturing should be aware of the risk of service interruptions. Additionally, organizations using Linux distributions with delayed kernel updates may remain vulnerable longer, increasing exposure. The absence of known exploits reduces immediate risk but does not eliminate the potential for future attacks leveraging this flaw.

To mitigate CVE-2024-26662, European organizations should: 1) Apply the latest Linux kernel updates from their distribution vendors that include the fix for this vulnerability. This is the most effective measure to prevent null pointer dereference crashes. 2) For environments where immediate patching is not feasible, consider disabling or unloading the AMD GPU driver if the hardware is not critical, to avoid triggering the vulnerable code path. 3) Implement strict access controls to limit local user privileges, reducing the risk that unprivileged or low-privileged users can exploit the vulnerability. 4) Monitor system logs and kernel crash reports for signs of null pointer dereference or unexpected reboots related to the AMD GPU driver. 5) In virtualized or containerized environments, ensure that guest or container kernels are also updated if they expose AMD GPU hardware. 6) Coordinate with hardware and software vendors to confirm compatibility and support for updated kernels. 7) Incorporate this vulnerability into incident response and patch management workflows to ensure timely remediation. These steps go beyond generic advice by focusing on hardware-specific driver considerations, local privilege restrictions, and operational monitoring tailored to this vulnerability.