Linux Kernel up to 6.12.15/6.13.3/6.14-rc2 amdkfd amdgpu_amdkfd_free_gtt_mem type confusion

Summaryinfo

A vulnerability described as problematic has been identified in Linux Kernel up to 6.12.15/6.13.3/6.14-rc2. This issue affects the function amdgpu_amdkfd_free_gtt_mem of the component amdkfd. Such manipulation leads to type confusion. This vulnerability is referenced as CVE-2025-21842. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.15/6.13.3/6.14-rc2 and classified as critical. Affected by this issue is the function amdgpu_amdkfd_free_gtt_mem of the component amdkfd. The manipulation with an unknown input leads to a type confusion vulnerability. Using CWE to declare the problem leads to CWE-843. The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: amdkfd: properly free gang_ctx_bo when failed to init user queue The destructor of a gtt bo is declared as void amdgpu_amdkfd_free_gtt_mem(struct amdgpu_device *adev, void **mem_obj); Which takes void** as the second parameter. GCC allows passing void* to the function because void* can be implicitly casted to any other types, so it can pass compiling. However, passing this void* parameter into the function's execution process(which expects void** and dereferencing void**) will result in errors.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-21842 since 12/29/2024. The exploitation is known to be easy. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/16/2026).

The vulnerability scanner Nessus provides a plugin with the ID 250066 (Linux Distros Unpatched Vulnerability : CVE-2025-21842), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.16, 6.13.4 or 6.14-rc3 eliminates this vulnerability. Applying the patch ae5ab1c1ae504f622cc1ff48830a9ed48428146d/091a68c58c1bbd2ab7d05d1b32c1306394ec691d/a33f7f9660705fb2ecf3467b2c48965564f392ce 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 (250066) and CERT Bund (WID-SEC-2025-0499). Once again VulDB remains the best source for vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• SolarWinds Security Event Manager
• 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
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.13.0
• 6.13.1
• 6.13.2
• 6.13.3
• 6.14-rc1
• 6.14-rc2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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