CVE-2024-50141: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-50141 affects the Linux kernel's ACPI Platform Runtime Mechanism (PRM) implementation. The vulnerability was discovered when the PRMT (Platform Runtime Mechanism Table) was finding a block of type EFI_CONVENTIONAL_MEMORY instead of the correct EFI_MEMORY_RUNTIME block type for runtime services, as specified in Section 2.2.2 of the UEFI Specification. This issue affects Linux kernel versions from 5.14 up to (excluding) 6.11.6 (NVD).

The vulnerability occurs in the Linux kernel's ACPI PRM handler where the physical-to-virtual address (PA-VA) mapping translation for EFI runtime services is incorrectly handled. When the PRM handler, which is a runtime service, is called, it causes an exception due to improper memory type allocation. The issue manifests as a paging request error in the EFI runtime service with the error message: 'Unable to handle paging request in EFI runtime service' (Kernel Patch). The CVSS v3.1 Base Score is 5.5 MEDIUM (Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) (NVD).

When the vulnerability is triggered, it results in a failure during error handling when the PRM handler is called without proper memory allocation. This can lead to system instability and potential denial of service conditions. The issue specifically affects the system's ability to properly handle EFI runtime services (Kernel Patch).

The issue has been fixed in the Linux kernel through a patch that ensures PRMT finds a block with EFI_MEMORY_RUNTIME for PRM handler and PRM context. If no suitable block is found, a warning message is printed, and the procedure continues to manage the next PRM handler. The fix ensures that the PRM handler and context are properly mapped in the virtual address space during runtime (Kernel Patch).