CVE-2025-39899 Affecting kernel-uek-debug-modules package, versions <0:6.12.0-105.51.5.el9uek


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.02% (6th percentile)

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  • Snyk IDSNYK-ORACLE9-KERNELUEKDEBUGMODULES-13869193
  • published10 Nov 2025
  • disclosed1 Oct 2025

Introduced: 1 Oct 2025

CVE-2025-39899  (opens in a new tab)

How to fix?

Upgrade Oracle:9 kernel-uek-debug-modules to version 0:6.12.0-105.51.5.el9uek or higher.
This issue was patched in ELSA-2025-25754.

NVD Description

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

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

mm/userfaultfd: fix kmap_local LIFO ordering for CONFIG_HIGHPTE

With CONFIG_HIGHPTE on 32-bit ARM, move_pages_pte() maps PTE pages using kmap_local_page(), which requires unmapping in Last-In-First-Out order.

The current code maps dst_pte first, then src_pte, but unmaps them in the same order (dst_pte, src_pte), violating the LIFO requirement. This causes the warning in kunmap_local_indexed():

WARNING: CPU: 0 PID: 604 at mm/highmem.c:622 kunmap_local_indexed+0x178/0x17c addr != __fix_to_virt(FIX_KMAP_BEGIN + idx)

Fix this by reversing the unmap order to respect LIFO ordering.

This issue follows the same pattern as similar fixes:

  • commit eca6828403b8 ("crypto: skcipher - fix mismatch between mapping and unmapping order")
  • commit 8cf57c6df818 ("nilfs2: eliminate staggered calls to kunmap in nilfs_rename")

Both of which addressed the same fundamental requirement that kmap_local operations must follow LIFO ordering.

CVSS Base Scores

version 3.1