CyberAlerts is shutting down on June 30th, 2025. Thank you for your support!

CVE-2024-44965: x86/mm: Fix pti_clone_pgtable() alignment assumption

5.5 CVSS

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.

Classification

CVE ID: CVE-2024-44965

CVSS Base Severity: MEDIUM

CVSS Base Score: 5.5

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.07% (probability of being exploited)

EPSS Percentile: 21.0% (scored less or equal to compared to others)

EPSS Date: 2025-06-02 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: false

References

Timeline

2025-05-04 10:40:17 UTC
CVE

x86/mm: Fix pti_clone_pgtable() alignment assumption