CVE-2025-39877 Affecting kernel-default-vdso package, versions <6.12.0-160000.6.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.04% (10th percentile)

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  • Snyk IDSNYK-SLES1600-KERNELDEFAULTVDSO-13941235
  • published14 Nov 2025
  • disclosed6 Nov 2025

Introduced: 6 Nov 2025

NewCVE-2025-39877  (opens in a new tab)

How to fix?

Upgrade SLES:16.0.0 kernel-default-vdso to version 6.12.0-160000.6.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-default-vdso package and not the kernel-default-vdso package as distributed by SLES. See How to fix? for SLES:16.0.0 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