CVE-2024-44965

x86/mm: Fix pti_clone_pgtable() alignment assumption

Published Sep 4, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

x86/mm: Fix pti_clone_pgtable() alignment assumption

Guenter reported dodgy crashes on an i386-nosmp build using GCC-11
that had the form of endless traps until entry stack exhaust and then
#DF from the stack guard.

It turned out that pti_clone_pgtable() had alignment assumptions on
the start address, notably it hard assumes start is PMD aligned. This
is true on x86_64, but very much not true on i386.

These assumptions can cause the end condition to malfunction, leading
to a 'short' clone. Guess what happens when the user mapping has a
short copy of the entry text?

Use the correct increment form for addr to avoid alignment
assumptions.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-3912-1 linux security update
Debian DLA Debian DLA DLA-4008-1 linux-6.1 security update
Ubuntu USN Ubuntu USN USN-7088-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7088-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7088-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7088-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7088-5 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7100-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7100-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7119-1 Linux kernel (IoT) vulnerabilities
Ubuntu USN Ubuntu USN USN-7123-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7144-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-7154-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7155-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-7156-1 Linux kernel (GKE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7154-2 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7194-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7196-1 Linux kernel (Azure) vulnerabilities
History
Type Values Removed Values Added
Metrics epss

{'score': 0.00064}

epss

{'score': 0.00067}

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Type Values Removed Values Added
Weaknesses CWE-119
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: x86/mm: Fix pti_clone_pgtable() alignment assumption Guenter reported dodgy crashes on an i386-nosmp build using GCC-11 that had the form of endless traps until entry stack exhaust and then #DF from the stack guard. It turned out that pti_clone_pgtable() had alignment assumptions on the start address, notably it hard assumes start is PMD aligned. This is true on x86_64, but very much not true on i386. These assumptions can cause the end condition to malfunction, leading to a 'short' clone. Guess what happens when the user mapping has a short copy of the entry text? Use the correct increment form for addr to avoid alignment assumptions.
Title x86/mm: Fix pti_clone_pgtable() alignment assumption
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 15, 2026, 12:49 AM
Reserved
Aug 21, 2024, 5:34 AM
Status
Modified
Published
Sep 4, 2024, 7:15 PM
Modified
Oct 15, 2026, 1:18 AM
Severity
Moderate
Public date
Sep 4, 2024, 12:00 AM