CVE-2025-21694 Affecting linux-6.1 package, versions <6.1.128-1~deb11u1


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.04% (6th percentile)

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  • Snyk IDSNYK-DEBIAN11-LINUX61-9055775
  • published3 Mar 2025
  • disclosed12 Feb 2025

Introduced: 12 Feb 2025

NewCVE-2025-21694  (opens in a new tab)

How to fix?

Upgrade Debian:11 linux-6.1 to version 6.1.128-1~deb11u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.1 package and not the linux-6.1 package as distributed by Debian. See How to fix? for Debian:11 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

fs/proc: fix softlockup in __read_vmcore (part 2)

Since commit 5cbcb62dddf5 ("fs/proc: fix softlockup in __read_vmcore") the number of softlockups in __read_vmcore at kdump time have gone down, but they still happen sometimes.

In a memory constrained environment like the kdump image, a softlockup is not just a harmless message, but it can interfere with things like RCU freeing memory, causing the crashdump to get stuck.

The second loop in __read_vmcore has a lot more opportunities for natural sleep points, like scheduling out while waiting for a data write to happen, but apparently that is not always enough.

Add a cond_resched() to the second loop in __read_vmcore to (hopefully) get rid of the softlockups.

CVSS Base Scores

version 3.1