CVE-2025-39877 Affecting kernel-uek-debug package, versions <0:6.12.0-105.51.5.el9uek


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.04% (10th percentile)

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  • Snyk IDSNYK-ORACLE9-KERNELUEKDEBUG-13870566
  • published10 Nov 2025
  • disclosed23 Sept 2025

Introduced: 23 Sep 2025

CVE-2025-39877  (opens in a new tab)

How to fix?

Upgrade Oracle:9 kernel-uek-debug 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 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:

mm/damon/sysfs: fix use-after-free in state_show()

state_show() reads kdamond->damon_ctx without holding damon_sysfs_lock. This allows a use-after-free race:

CPU 0 CPU 1


state_show() damon_sysfs_turn_damon_on() ctx = kdamond->damon_ctx; mutex_lock(&damon_sysfs_lock); damon_destroy_ctx(kdamond->damon_ctx); kdamond->damon_ctx = NULL; mutex_unlock(&damon_sysfs_lock); damon_is_running(ctx); /* ctx is freed / mutex_lock(&ctx->kdamond_lock); / UAF */

(The race can also occur with damon_sysfs_kdamonds_rm_dirs() and damon_sysfs_kdamond_release(), which free or replace the context under damon_sysfs_lock.)

Fix by taking damon_sysfs_lock before dereferencing the context, mirroring the locking used in pid_show().

The bug has existed since state_show() first accessed kdamond->damon_ctx.

CVSS Base Scores

version 3.1