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Fencer Vulns
medium 5.5

CVE-2024-44948 json

x86/mtrr: Check if fixed MTRRs exist before saving them

published 2024-09-04 2 y ago modified 2026-10-15 25 d ago also EUVD-2024-41153

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

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 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.

Patch / fix

  • Linux Linux 4.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.105, 6.6.46, 6.10.5, 6.11
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem V1.1.1
  • linux Debian 12 6.1.106-1
  • linux Debian 14, Debian 13 6.10.6-1

debian advisories DEBIAN-CVE-2024-44948

  • linux Ubuntu 20.04 LTS 5.4.0-200.220
  • linux Ubuntu 22.04 LTS 5.15.0-125.135
  • linux Ubuntu 24.04 LTS 6.8.0-50.51
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1135.145
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1072.78
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1020.22
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1139.148
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1071.79

ubuntu advisories UBUNTU-CVE-2024-44948

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-rt Linux Micro 6.0 6.4.0-11.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-11.1
  • kernel-livepatch-MICRO-6-0-RT_Update_3 Linux Micro 6.0 1-1.2
  • kernel-source Linux Micro 6.0 6.4.0-20.1
  • kernel-default Linux Micro 6.0 6.4.0-20.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-20.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-livepatch-MICRO-6-0_Update_3 Linux Micro 6.0 1-1.2

suse advisories SUSE-SU-2025:20077-1SUSE-SU-2025:20073-1SUSE-SU-2024:3592-1SUSE-SU-2024:3591-1SUSE-SU-2024:3587-1SUSE-SU-2024:3569-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-44948 updated cvss 5.5

kernel: x86/mtrr: Check if fixed MTRRs exist before saving them

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-24-102-01 updated cvss 5.5

Siemens SIMATIC S7-1500 TM MFP

  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
    affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.