CVE-2024-26843: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-26843 is a vulnerability discovered in the Linux kernel's EFI runtime services implementation. The vulnerability was disclosed on April 17, 2024, and affects the handling of soft-reserved region sizes in the EFI firmware interface. The issue specifically occurs when dealing with memory regions greater than or equal to 4GB in size (NVD).

The vulnerability stems from an integer overflow condition in the EFI runtime services code. The issue occurs when the md_size variable, originally declared as an integer, is used to store the size of memory pages that could exceed 4GB. The fix involves changing the variable type from int to u64 to properly handle large memory regions (Kernel Commit). The vulnerability has been assigned a CVSS v3.1 base score of 6.0 (Medium) with the vector string CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:H (CISA-ADP).

Due to the integer overflow vulnerability, certain EFI-related memory reservations might receive a size other than expected, potentially leading to a denial of service condition. The vulnerability primarily affects systems utilizing EFI firmware interfaces (Red Hat).

The vulnerability has been patched in various Linux kernel versions. The fix involves modifying the data type of the md_size variable from int to u64 in the affected EFI runtime service code. Users are advised to update their Linux kernel to the latest version that includes the security patch (Kernel Commit).