CVE-2025-21811 Affecting kernel-uek-debug package, versions <0:6.12.0-101.33.4.3.el9uek


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.04% (9th percentile)

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  • Snyk IDSNYK-ORACLE9-KERNELUEKDEBUG-10779786
  • published18 Jul 2025
  • disclosed27 Feb 2025

Introduced: 27 Feb 2025

CVE-2025-21811  (opens in a new tab)

How to fix?

Upgrade Oracle:9 kernel-uek-debug to version 0:6.12.0-101.33.4.3.el9uek or higher.
This issue was patched in ELSA-2025-20480.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-uek-debug package and not the kernel-uek-debug 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:

nilfs2: protect access to buffers with no active references

nilfs_lookup_dirty_data_buffers(), which iterates through the buffers attached to dirty data folios/pages, accesses the attached buffers without locking the folios/pages.

For data cache, nilfs_clear_folio_dirty() may be called asynchronously when the file system degenerates to read only, so nilfs_lookup_dirty_data_buffers() still has the potential to cause use after free issues when buffers lose the protection of their dirty state midway due to this asynchronous clearing and are unintentionally freed by try_to_free_buffers().

Eliminate this race issue by adjusting the lock section in this function.

CVSS Base Scores

version 3.1