CVE-2026-46007: hwmon: (powerz) Avoid cacheline sharing for DMA buffer

Q: Which systems are exposed to this issue?

Systems running the Linux kernel with the hwmon powerz driver in use are relevant. The issue depends on architectures where the DMA transfer buffer can share a cacheline with a following mutex.

Q: What conditions are required for the problem to occur?

The powerz driver must use its transfer buffer for DMA, and the buffer must share a cacheline with the mutex that follows it. Exploitation requires local access with low privileges; no user interaction is required.

Q: What is the expected impact?

The reported impact is denial of service only, with high availability impact. No confidentiality or integrity impact is indicated.

Q: What change addresses the issue?

The fix uses high-level DMA helpers so the DMA buffer cannot share a cacheline with the mutex. The referenced stable kernel commits contain the remediation.

Published May 27, 2026

Updated

In the Linux kernel, the following vulnerability has been resolved:

hwmon: (powerz) Avoid cacheline sharing for DMA buffer

Depending on the architecture the transfer buffer may share a cacheline with the following mutex. As the buffer may be used for DMA, that is problematic.

Use the high-level DMA helpers to make sure that cacheline sharing can not happen.

Also drop the comment, as the helpers are documentation enough.

https://sashiko.dev/#/message/20260408175814.934BFC19421%40smtp.kernel.org

Affected Software

4 affected components

Linux Linux kernel

Linux Linux kernel>=6.7<6.12.88

Linux Linux kernel>=6.13<6.18.30

Linux Linux kernel>=6.19<7.0.4

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Compensating control
Use the high-level DMA helpers for the transfer buffer to prevent cacheline sharing when the buffer may be used for DMA.

Event History

May 27, 2026

CVE Published

via MITRE·12:56 PM

Data Sourced

via MITRE·12:56 PM

Description

Data Sourced

via NVD·02:17 PM

RemedyDescriptionSeverityAffected Software

Frequently Asked Questions

Which systems are exposed to this issue?

Systems running the Linux kernel with the hwmon powerz driver in use are relevant. The issue depends on architectures where the DMA transfer buffer can share a cacheline with a following mutex.

What conditions are required for the problem to occur?

The powerz driver must use its transfer buffer for DMA, and the buffer must share a cacheline with the mutex that follows it. Exploitation requires local access with low privileges; no user interaction is required.

What is the expected impact?

The reported impact is denial of service only, with high availability impact. No confidentiality or integrity impact is indicated.

What change addresses the issue?

The fix uses high-level DMA helpers so the DMA buffer cannot share a cacheline with the mutex. The referenced stable kernel commits contain the remediation.

CVE-2026-46007: hwmon: (powerz) Avoid cacheline sharing for DMA buffer

Affected Software

Remediation

Event History

Frequently Asked Questions

Which systems are exposed to this issue?

What conditions are required for the problem to occur?

What is the expected impact?

What change addresses the issue?

Company

Resources

Contact

Frequently Asked Questions

Which systems are exposed to this issue?

What conditions are required for the problem to occur?

What is the expected impact?

What change addresses the issue?