CVE-2024-44948: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: x86/mtrr: Check if fixed MTRRs exist before saving them MTRRs have an obsolete fixed variant for fine grained caching control of the 640K-1MB region that uses separate MSRs. This fixed variant has a separate capability bit in the MTRR capability MSR. So far all x86 CPUs which support MTRR have this separate bit set, so it went unnoticed that mtrr_save_state() does not check the capability bit before accessing the fixed MTRR MSRs. Though on a CPU that does not support the fixed MTRR capability this results in a #GP. The #GP itself is harmless because the RDMSR fault is handled gracefully, but results in a WARN_ON(). Add the missing capability check to prevent this.

Affected products

• Linux Linux Kernel: from 2.6.22, before 4.19.320 (fixed in 4.19.320); from 4.20, before 5.4.282 (fixed in 5.4.282); from 5.5, before 5.10.224 (fixed in 5.10.224); from 5.11, before 5.15.165 (fixed in 5.15.165); from 5.16, before 6.1.105 (fixed in 6.1.105); from 6.2, before 6.6.46 (fixed in 6.6.46); …

Published 2024-09-04. Last modified 2026-06-17.