CVE-2024-50141 is a vulnerability identified in the Linux kernel related to the handling of ACPI Platform Runtime Mechanism (PRM) within the EFI (Extensible Firmware Interface) runtime services context. The issue arises because the PRMT (Platform Runtime Mechanism Table) incorrectly identifies a memory block of type EFI_CONVENTIONAL_MEMORY instead of EFI_MEMORY_RUNTIME when mapping physical to virtual addresses for PRM handlers and their contexts. According to the UEFI Specification, runtime services must operate on memory regions marked with the EFI_MEMORY_RUNTIME attribute to ensure proper virtual address mapping during runtime. Using an incorrect memory type leads to exceptions and paging errors when the PRM handler is invoked, as the memory region is not properly remapped for runtime use by the firmware. This manifests as kernel warnings and potential failures in error handling during runtime service calls. The vulnerability is rooted in firmware memory management and kernel interaction, specifically in the file drivers/firmware/efi/runtime-wrappers.c. The fix involves ensuring that the PRMT locates and uses memory blocks with the EFI_MEMORY_RUNTIME attribute for PRM handlers and contexts, preventing paging faults and maintaining stable runtime service operation. If no suitable EFI_MEMORY_RUNTIME block is found, the kernel logs a warning but continues processing other handlers, reducing the risk of a complete system failure. This vulnerability does not currently have known exploits in the wild and lacks a CVSS score, but it affects Linux kernel versions identified by the commit cefc7ca46235f01d5233e3abd4b79452af01d9e9 and similar revisions. The issue is technical and low-level, involving firmware and kernel memory management during EFI runtime services, which are critical for system stability and security during OS runtime interactions with firmware.

For European organizations, the impact of CVE-2024-50141 primarily concerns systems running Linux kernels with affected versions on hardware utilizing UEFI firmware and ACPI runtime services. The vulnerability can cause kernel exceptions and failures during EFI runtime service calls, potentially leading to system instability or crashes. While it does not directly enable privilege escalation or remote code execution, the instability can disrupt critical services, especially in environments relying on Linux servers for infrastructure, cloud services, or embedded systems. Organizations in sectors such as finance, healthcare, telecommunications, and critical infrastructure could experience operational disruptions if affected systems encounter runtime service failures. Additionally, since EFI runtime services are involved in secure boot and firmware interactions, improper handling could indirectly affect system integrity or complicate firmware updates and error recovery. However, the lack of known exploits and the requirement for specific firmware and kernel configurations limit the immediate risk. The vulnerability is more likely to impact system reliability and availability rather than confidentiality or integrity directly. European organizations with large Linux deployments, especially those using custom or older firmware implementations, should prioritize patching to avoid unexpected system behavior.

1. Apply the official Linux kernel patches that address CVE-2024-50141 as soon as they become available from trusted sources or Linux distribution vendors. 2. Verify that firmware (UEFI) on affected systems is up to date, as firmware updates may improve EFI_MEMORY_RUNTIME memory region management and compatibility. 3. Conduct thorough testing of kernel updates in staging environments to ensure that EFI runtime services operate correctly without triggering paging faults. 4. Monitor kernel logs for warnings related to EFI runtime services and PRM handlers to detect potential issues early. 5. For critical systems, consider implementing redundancy and failover mechanisms to mitigate the impact of potential runtime service failures. 6. Engage with hardware vendors to confirm compliance with UEFI specifications regarding EFI_MEMORY_RUNTIME attributes and runtime memory remapping. 7. Educate system administrators about the importance of maintaining synchronized firmware and kernel versions to prevent runtime service incompatibilities. 8. Avoid running unsupported or heavily customized kernels that may not include the fix or handle EFI runtime services correctly.