Use After Free Affecting kernel-uek-debug-modules package, versions <0:6.12.0-102.36.5.2.el9uek


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.11% (31st percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about Use After Free vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-ORACLE9-KERNELUEKDEBUGMODULES-10780940
  • published18 Jul 2025
  • disclosed20 Jan 2025

Introduced: 20 Jan 2025

CVE-2025-21655  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Oracle:9 kernel-uek-debug-modules to version 0:6.12.0-102.36.5.2.el9uek or higher.
This issue was patched in ELSA-2025-20530.

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:

io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period

io_eventfd_do_signal() is invoked from an RCU callback, but when dropping the reference to the io_ev_fd, it calls io_eventfd_free() directly if the refcount drops to zero. This isn't correct, as any potential freeing of the io_ev_fd should be deferred another RCU grace period.

Just call io_eventfd_put() rather than open-code the dec-and-test and free, which will correctly defer it another RCU grace period.

CVSS Base Scores

version 3.1