CVE-2025-38704 Affecting kernel-uek package, versions <0:6.12.0-104.43.4.2.el9uek


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.03% (6th percentile)

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  • Snyk IDSNYK-ORACLE9-KERNELUEK-13567823
  • published16 Oct 2025
  • disclosed4 Sept 2025

Introduced: 4 Sep 2025

CVE-2025-38704  (opens in a new tab)

How to fix?

Upgrade Oracle:9 kernel-uek to version 0:6.12.0-104.43.4.2.el9uek or higher.
This issue was patched in ELSA-2025-20662.

NVD Description

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

rcu/nocb: Fix possible invalid rdp's->nocb_cb_kthread pointer access

In the preparation stage of CPU online, if the corresponding the rdp's->nocb_cb_kthread does not exist, will be created, there is a situation where the rdp's rcuop kthreads creation fails, and then de-offload this CPU's rdp, does not assign this CPU's rdp->nocb_cb_kthread pointer, but this rdp's->nocb_gp_rdp and rdp's->rdp_gp->nocb_gp_kthread is still valid.

This will cause the subsequent re-offload operation of this offline CPU, which will pass the conditional check and the kthread_unpark() will access invalid rdp's->nocb_cb_kthread pointer.

This commit therefore use rdp's->nocb_gp_kthread instead of rdp_gp's->nocb_gp_kthread for safety check.

CVSS Base Scores

version 3.1