CVE-2025-21676

Medium

In the Linux kernel, the following vulnerability has been resolved: net: fec: handle page_pool_dev_alloc_pages error The fec_enet_update_cbd function calls page_pool_dev_alloc_pages but did not handle the case when it returned NULL. There was a WARN_ON(!new_page) but it would still proceed to use the NULL pointer and then crash. This case does seem somewhat rare but when the system is under memory pressure it can happen. One case where I can duplicate this with some frequency is when writing over a smbd share to a SATA HDD attached to an imx6q. Setting /proc/sys/vm/min_free_kbytes to higher values also seems to solve the problem for my test case. But it still seems wrong that the fec driver ignores the memory allocation error and can crash. This commit handles the allocation error by dropping the current packet.

Package Linux Kernel
Published 2025-01-31
Last modified 2026-03-25
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-476

CVE-2025-21676 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.1 and later are affected. Fixed in 6.1.167, 6.6.74, 6.12.11, 6.13 and their respective stable series.

Affected from
≥ 6.1
Fixed in
✓ 6.1.167 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-2025-21676 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

4 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2025-21676?

    CVE-2025-21676 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 6.1 onward and has been patched in 6.1.167, 6.6.74, 6.12.11 and others. CVE-2025-21676 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-21676?

    CVE-2025-21676 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-2025-21676?

    Yes — CVE-2025-21676 has been patched. Fixed versions include 6.1.167, 6.6.74, 6.12.11 and others. If you are running Linux kernel 6.1 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-21676 actively exploited?

    No — CVE-2025-21676 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is NULL Pointer Dereference (CWE-476)?

    The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →

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