CVE-2026-89741
Received Received - Intake

Revert of Media Device Registration Fix in Linux Kernel

Vulnerability report for CVE-2026-89741, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-09-11

Last updated on: 2026-09-11

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: Revert "media: v4l2-dev: fix error handling in __video_register_device()" This reverts commit 2a934fdb01db6458288fc9386d3d8ceba6dd551a. The intentions of that patch were good, but it doesn't work. The idea is that if device_register fails, you have to do a put_device to let the ref counter release resources. However, the V4L2 API says that if video_register_device() fails, then you have to call video_device_release(), which kfree()s the video_device struct. But the put_device() will already have freed the struct, so you end up in a double-free scenario. There is not really a good way of fixing this without breaking video_register_device() into two parts, one that initializes everything, and one that does the actual device_register, and then converting all V4L2 drivers to this new model. That is a massive job, and it is very unlikely that device_register will fail. So rather than ending up in a double-free scenario, just revert this patch, and in that case we'll have a small memory leak. Which is a lot more robust.

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Meta Information

Published
2026-09-11
Last Modified
2026-09-11
Generated
2026-09-12
AI Q&A
2026-09-12
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

Helpful Resources

Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a flawed patch that attempted to fix error handling in video device registration. The patch tried to release resources if device registration failed, but it caused a double-free scenario because the V4L2 API requires calling video_device_release() on failure, which frees the device structure. The patch's approach conflicted with this requirement, leading to crashes.

Detection Guidance

This vulnerability is specific to the Linux kernel's V4L2 subsystem and does not have network-based detection methods. Detection involves checking the kernel version and verifying if the vulnerable commit is present. Use commands like 'uname -r' to check the kernel version and 'git log' in the kernel source to inspect for the reverted commit 2a934fdb01db6458288fc9386d3d8ceba6dd551a.

Impact Analysis

This vulnerability could cause system instability or crashes if a video device registration fails. The double-free scenario may lead to kernel panics or unexpected behavior, potentially disrupting applications relying on video devices. However, the risk is considered low since device_register failures are rare.

Mitigation Strategies

Apply the latest kernel updates from your Linux distribution to ensure the reverted commit is included. If updates are unavailable, avoid using V4L2 drivers until a patch is applied. Monitor vendor advisories for kernel updates addressing this issue.

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