CVE-2024-57931: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-57931 affects the Linux kernel's SELinux subsystem, specifically related to the handling of extended permissions. The vulnerability was discovered and disclosed on January 21, 2025. The issue occurs when evaluating extended permissions in SELinux, where unknown permissions would trigger a BUG() call instead of being gracefully handled (NVD).

The vulnerability exists in the SELinux subsystem's permission evaluation mechanism. When encountering unknown extended permissions, the system would call BUG() instead of gracefully handling the situation. The fix modifies the behavior to ignore unknown permissions and continue operation, ensuring that future permissions can be added without interfering with older kernels. The patch specifically modifies the servicescomputexperms_decision function in the security/selinux/ss/services.c file (Kernel Commit).

The vulnerability could potentially cause system crashes when encountering unknown extended permissions in SELinux, affecting system stability and availability. This would occur when new permissions are added in newer kernels but accessed by older kernel versions (Debian Tracker).

The issue has been fixed in multiple Linux kernel versions through backported patches. Ubuntu, Debian, and other distributions have released or are in the process of releasing updated kernel packages. Users should update their systems to the patched versions. For Ubuntu, fixes are being worked on for versions 24.04 LTS, 22.04 LTS, and 20.04 LTS (Ubuntu Security).