CVE-2025-68209
In the Linux kernel, the following vulnerability has been resolved: mlx5: Fix default values in create CQ Currently, CQs without a completion function are assigned the mlx5_add_cq_to_tasklet func…
Overview
CVE-2025-68209 is a known-severity vulnerability. It was published on December 16, 2025.
Technical description
In the Linux kernel, the following vulnerability has been resolved:
mlx5: Fix default values in create CQ
Currently, CQs without a completion function are assigned the
mlx5_add_cq_to_tasklet function by default. This is problematic since
only user CQs created through the mlx5_ib driver are intended to use
this function.
Additionally, all CQs that will use doorbells instead of polling for
completions must call mlx5_cq_arm. However, the default CQ creation flow
leaves a valid value in the CQ's arm_db field, allowing FW to send
interrupts to polling-only CQs in certain corner cases.
These two factors would allow a polling-only kernel CQ to be triggered
by an EQ interrupt and call a completion function intended only for user
CQs, causing a null pointer exception.
Some areas in the driver have prevented this issue with one-off fixes
but did not address the root cause.
This patch fixes the described issue by adding defaults to the create CQ
flow. It adds a default dummy completion func
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
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Frequently asked questions
What is CVE-2025-68209?
CVE-2025-68209 is a known-severity vulnerability. It was published on December 16, 2025.
How severe is CVE-2025-68209?
CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.
How do I fix or remediate CVE-2025-68209?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-68209?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2025-68209 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.