---
id: CVE-2024-44948
title: |-
  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…
summary: |-
  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…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 2.6.22, < 4.19.320'
  - 'linux_kernel >= 4.20, < 5.4.282'
  - 'linux_kernel >= 5.5, < 5.10.224'
  - 'linux_kernel >= 5.11, < 5.15.165'
  - 'linux_kernel >= 5.16, < 6.1.105'
  - 'linux_kernel >= 6.2, < 6.6.46'
  - 'linux_kernel >= 6.7, < 6.10.5'
  - linux_kernel = 6.11
patched:
  - linux_kernel 6.10.5
published: '2024-09-04'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T01:18:50.100'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-44948'
references:
  - url: 'https://git.kernel.org/stable/c/06c1de44d378ec5439db17bf476507d68589bfe9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/34f36e6ee5bd7eff8b2adcd9fcaef369f752d82e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/388f1c954019f253a8383f7eb733f38d541e10b6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/450b6b22acdaac67a18eaf5ed498421ffcf10051'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8a90d3fc7c24608548d3a750671f9dac21d1a462'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8aa79dfb216b865e96ff890bc4ea71650f9bc8d7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/919f18f961c03d6694aa726c514184f2311a4614'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ca7d00c5656d1791e28369919e3e10febe9c3b16'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00242
epssPercentile: 0.15279
ingestedAt: '2026-10-15T03:30:12.739Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2024-09-10T17:40:29.464386Z'
---

## Overview

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

- `linux_kernel >= 2.6.22, < 4.19.320`
- `linux_kernel >= 4.20, < 5.4.282`
- `linux_kernel >= 5.5, < 5.10.224`
- `linux_kernel >= 5.11, < 5.15.165`
- `linux_kernel >= 5.16, < 6.1.105`
- `linux_kernel >= 6.2, < 6.6.46`
- `linux_kernel >= 6.7, < 6.10.5`
- `linux_kernel = 6.11`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.10.5`