Use After Free Affecting kernel-source-azure package, versions <5.14.21-150500.33.72.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.04% (6th percentile)

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  • Snyk IDSNYK-SLES155-KERNELSOURCEAZURE-8377396
  • published14 Nov 2024
  • disclosed13 Nov 2024

Introduced: 13 Nov 2024

CVE-2022-48991  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade SLES:15.5 kernel-source-azure to version 5.14.21-150500.33.72.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-source-azure package and not the kernel-source-azure package as distributed by SLES. See How to fix? for SLES:15.5 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths

Any codepath that zaps page table entries must invoke MMU notifiers to ensure that secondary MMUs (like KVM) don't keep accessing pages which aren't mapped anymore. Secondary MMUs don't hold their own references to pages that are mirrored over, so failing to notify them can lead to page use-after-free.

I'm marking this as addressing an issue introduced in commit f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages"), but most of the security impact of this only came in commit 27e1f8273113 ("khugepaged: enable collapse pmd for pte-mapped THP"), which actually omitted flushes for the removal of present PTEs, not just for the removal of empty page tables.

CVSS Scores

version 3.1