CVE-2025-21975: linux kernel Null Dereference — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: handle errors in mlx5_chains_create_table() In mlx5_chains_create_table(), the return value of mlx5_get_fdb_sub_ns() and mlx5_get_flow_namespace() must be checked to prevent NULL pointer dereferences. If either function fails, the function should log error message with mlx5_core_warn() and return error pointer.

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.6 — 5.10.236
linux	linux_kernel	5.11 — 5.15.180
linux	linux_kernel	5.16 — 6.1.132
linux	linux_kernel	6.2 — 6.6.84
linux	linux_kernel	6.7 — 6.12.20
linux	linux_kernel	6.13 — 6.13.8
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/093b4aaec97ec048623e3fe1e516fc45a954d412 https://git.kernel.org/stable/c/1598307c914ba3d2642a2b03d1ff11efbdb7c6c2 https://git.kernel.org/stable/c/15bdd93728369b2c8942a8e5d549d4b5dc04a2d9 https://git.kernel.org/stable/c/1d34296409a519b4027750e3e82d9e19553a7398 https://git.kernel.org/stable/c/29c419c64e9b396baeda1d8713d2aa3ba7c0acf6 https://git.kernel.org/stable/c/637105ef0d46fe5beac15aceb431da3ec832bb00 https://git.kernel.org/stable/c/eab0396353be1c778eba1c0b5180176f04dd21ce

Other References

https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html

Frequently Asked Questions

What is CVE-2025-21975? +

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: handle errors in mlx5_chains_create_table() In mlx5_chains_create_table(), the return value of mlx5_get_fdb_sub_ns() and mlx5_get_flow_namespace() must be checked to prevent NULL pointer dereferences. If either function fails, the function should log error message with mlx5_core_warn() and return error pointer. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2025-21975? +

CVE-2025-21975 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-21975? +

CVE-2025-21975 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-21975? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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