CVE-2025-21954

Medium

In the Linux kernel, the following vulnerability has been resolved: netmem: prevent TX of unreadable skbs Currently on stable trees we have support for netmem/devmem RX but not TX. It is not safe to forward/redirect an RX unreadable netmem packet into the device's TX path, as the device may call dma-mapping APIs on dma addrs that should not be passed to it. Fix this by preventing the xmit of unreadable skbs. Tested by configuring tc redirect: sudo tc qdisc add dev eth1 ingress sudo tc filter add dev eth1 ingress protocol ip prio 1 flower ip_proto \ tcp src_ip 192.168.1.12 action mirred egress redirect dev eth1 Before, I see unreadable skbs in the driver's TX path passed to dma mapping APIs. After, I don't see unreadable skbs in the driver's TX path passed to dma mapping APIs.

Package Linux Kernel
Published 2025-04-01
Last modified 2025-10-31
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

Weakness type

CWE-401

CVE-2025-21954 is a Memory Leak vulnerability

What is Memory Leak?

The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.12 and later are affected. Fixed in 6.12.20, 6.13.8, 6.14 and their respective stable series.

Affected from
≥ 6.12
Fixed in
✓ 6.12.20 6.12.x ✓ 6.13.8 6.13.x ✓ 6.14

References

The following references provide additional information about CVE-2025-21954 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2025-21954?

    CVE-2025-21954 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 6.12 onward and has been patched in 6.12.20, 6.13.8 and 6.14. CVE-2025-21954 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-21954?

    CVE-2025-21954 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-2025-21954?

    Yes — CVE-2025-21954 has been patched. Fixed versions include 6.12.20, 6.13.8 and 6.14. If you are running Linux kernel 6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-21954 actively exploited?

    No — CVE-2025-21954 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Memory Leak (CWE-401)?

    The product does not release memory after use, causing gradual resource exhaustion. View CWE-401 on MITRE CWE →

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