Use After Free Affecting kernel-debug-modules-extra package, versions <0:5.14.0-687.12.1.el9_8


Severity

Recommended
high

Based on Rocky Linux security rating.

Threat Intelligence

EPSS
0.01% (3rd percentile)

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  • Snyk IDSNYK-ROCKY9-KERNELDEBUGMODULESEXTRA-17111003
  • published31 May 2026
  • disclosed8 May 2026

Introduced: 8 May 2026

NewCVE-2026-43303  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Rocky-Linux:9 kernel-debug-modules-extra to version 0:5.14.0-687.12.1.el9_8 or higher.
This issue was patched in RLSA-2026:21556.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-debug-modules-extra package and not the kernel-debug-modules-extra package as distributed by Rocky-Linux. See How to fix? for Rocky-Linux:9 relevant fixed versions and status.

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

mm/page_alloc: clear page->private in free_pages_prepare()

Several subsystems (slub, shmem, ttm, etc.) use page->private but don't clear it before freeing pages. When these pages are later allocated as high-order pages and split via split_page(), tail pages retain stale page->private values.

This causes a use-after-free in the swap subsystem. The swap code uses page->private to track swap count continuations, assuming freshly allocated pages have page->private == 0. When stale values are present, swap_count_continued() incorrectly assumes the continuation list is valid and iterates over uninitialized page->lru containing LIST_POISON values, causing a crash:

KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107] RIP: 0010:__do_sys_swapoff+0x1151/0x1860

Fix this by clearing page->private in free_pages_prepare(), ensuring all freed pages have clean state regardless of previous use.

CVSS Base Scores

version 3.1