CVE-2024-26938 is a vulnerability identified in the Linux kernel, specifically within the Direct Rendering Manager (DRM) subsystem's Intel i915 graphics driver component. The issue arises in the function intel_bios_encoder_supports_dp_dual_mode(), which is responsible for determining whether a given display encoder supports DisplayPort dual-mode (DP++). The vulnerability occurs when the Video BIOS Table (VBT) is missing or does not declare the encoder in question, resulting in a NULL pointer for 'devdata'. Previously, this condition caused the kernel to 'oops' (crash) due to dereferencing a NULL pointer. The fix involves adding tolerance for a NULL 'devdata' pointer by bailing out early instead of crashing. While this prevents the kernel panic, it means the system cannot determine if the port supports DP++ functionality in such cases. The vulnerability is rooted in improper handling of missing or incomplete BIOS data, leading to a denial-of-service (DoS) condition via kernel crash. The patch was cherry-picked from commit 26410896206342c8a80d2b027923e9ee7d33b733 and is included in recent Linux kernel versions. There are no known exploits in the wild at this time, and no CVSS score has been assigned yet. The vulnerability affects Linux kernel versions identified by the commit hash 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and potentially others in the same release timeframe. This vulnerability is a stability and availability issue rather than a direct confidentiality or integrity compromise.

For European organizations, the primary impact of CVE-2024-26938 is a potential denial-of-service condition on Linux systems running the affected kernel versions with Intel integrated graphics using the i915 driver. A kernel oops can cause system instability, crashes, or reboots, disrupting business operations, especially in environments relying on Linux for critical infrastructure, servers, or workstations. Organizations using Linux-based desktop environments or embedded systems with Intel graphics may experience unexpected downtime or degraded user experience. While this vulnerability does not allow privilege escalation or data leakage, the availability impact can be significant in sectors such as finance, manufacturing, healthcare, and public services where Linux systems are prevalent. Additionally, the inability to detect DP++ support may affect display functionality or compatibility in some hardware setups, potentially impacting user productivity. Since no known exploits exist yet, the immediate risk is moderate, but the vulnerability should be addressed promptly to avoid future exploitation or accidental crashes.

European organizations should apply the official Linux kernel patches that address CVE-2024-26938 as soon as they become available in their distribution's kernel updates. Specifically, updating to the latest stable kernel versions that include the fix for the i915 driver is critical. System administrators should audit their Linux systems to identify those running affected kernel versions with Intel integrated graphics. For environments where immediate patching is not feasible, consider temporary mitigations such as disabling the affected graphics driver module if possible, or using alternative display drivers, though this may impact functionality. Monitoring system logs for kernel oops or crashes related to the i915 driver can help detect attempts to trigger this vulnerability. Additionally, organizations should maintain robust backup and recovery procedures to mitigate the impact of unexpected system crashes. Coordination with hardware vendors and Linux distribution maintainers is recommended to ensure timely updates and support. Finally, educating IT staff about this vulnerability and its symptoms will aid in rapid detection and response.