CVE-2025-21694

Medium

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.

Package Linux Kernel
Published 2025-02-12
Last modified 2026-05-12
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 5.4.279, 5.10.221, 5.15.162, 6.1.95, 6.6.35, 4.19.317, 6.9.6, 6.10 and later are affected. Fixed in 5.4.290, 5.10.234, 5.15.177, 6.1.127, 6.6.74, 6.12.11, 6.13 and their respective stable series.

Affected from
≥ 5.4.279 ≥ 5.10.221 ≥ 5.15.162 ≥ 6.1.95 ≥ 6.6.35 ≥ 4.19.317 ≥ 6.9.6 ≥ 6.10
Fixed in
✓ 5.4.290 5.4.x ✓ 5.10.234 5.10.x ✓ 5.15.177 5.15.x ✓ 6.1.127 6.1.x ✓ 6.6.74 6.6.x ✓ 6.12.11 6.12.x ✓ 6.13

References

The following references provide additional information about CVE-2025-21694 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

7 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2025-21694?

    CVE-2025-21694 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.4.279 onward and has been patched in 5.4.290, 5.10.234, 5.15.177 and others. CVE-2025-21694 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-21694?

    CVE-2025-21694 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2025-21694?

    Yes — CVE-2025-21694 has been patched. Fixed versions include 5.4.290, 5.10.234, 5.15.177 and others. If you are running Linux kernel 5.4.279 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-21694 actively exploited?

    No — CVE-2025-21694 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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