Red Hat: CVE-2024-44965: kernel: x86/mm: Fix pti_clone_pgtable() alignment assumption (Multiple Advisories)

Red Hat: CVE-2024-44965: kernel: x86/mm: Fix pti_clone_pgtable() alignment assumption (Multiple Advisories)

Severity

5

CVSS

(AV:L/AC:L/Au:S/C:N/I:N/A:C)

Published

09/04/2024

Created

12/06/2024

Added

12/05/2024

Modified

12/05/2024

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.

Solution(s)

• redhat-upgrade-kernel
• redhat-upgrade-kernel-rt

References

• CVE-2024-44965
• RHSA-2024:9315