Linux Kernel up to 6.12.9 virtuser platform_device_register_full memory leak

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.12.9. Impacted is the function platform_device_register_full of the component virtuser. Performing a manipulation results in memory leak. This vulnerability is identified as CVE-2025-21661. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.12.9. This affects the function platform_device_register_full of the component virtuser. The manipulation with an unknown input leads to a memory leak vulnerability. CWE is classifying the issue as CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: gpio: virtuser: fix missing lookup table cleanups When a virtuser device is created via configfs and the probe fails due to an incorrect lookup table, the table is not removed. This prevents subsequent probe attempts from succeeding, even if the issue is corrected, unless the device is released. Additionally, cleanup is also needed in the less likely case of platform_device_register_full() failure. Besides, a consistent memory leak in lookup_table->dev_id was spotted using kmemleak by toggling the live state between 0 and 1 with a correct lookup table. Introduce gpio_virtuser_remove_lookup_table() as the counterpart to the existing gpio_virtuser_make_lookup_table() and call it from all necessary points to ensure proper cleanup.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-21661 since 12/29/2024. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 231865 (Linux Distros Unpatched Vulnerability : CVE-2025-21661), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.10 eliminates this vulnerability. Applying the patch d72d0126b1f6981f6ce8b4247305f359958c11b5/a619cba8c69c434258ff4101d463322cd63e1bdc is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (231865) and CERT Bund (WID-SEC-2025-0155). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• Dell NetWorker
• Dell Avamar
• Dell PowerProtect Data Domain
• Open Source Linux Kernel
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Be aware that VulDB is the high quality source for vulnerability data.

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