# CVE-2025-21842: amdkfd: properly free gang_ctx_bo when failed to init user queue

> A type mismatch in the amdkfd driver causes a null pointer dereference when user queue initialization fails, leading to a kernel crash.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Mar 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2025-21842, DEBIAN-CVE-2025-21842, GHSA-583x-9h9h-f6f6, UBUNTU-CVE-2025-21842

## What is CVE-2025-21842?

CVE-2025-21842 is a high-severity vulnerability in Linux kernel, published on 7 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

## Which versions are affected by CVE-2025-21842?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-21842?

Apply the vendor's patch.

## Is CVE-2025-21842 being exploited?

There is no known exploitation of CVE-2025-21842 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-21842 and fix it if it is affected.

What it is: CVE-2025-21842 is a high-severity vulnerability in Linux kernel, published on 7 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-21842 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-21842/ (Markdown: https://insights.sbomify.com/CVE-2025-21842/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21842
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21842
- OSV: https://osv.dev/vulnerability/CVE-2025-21842

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21842/
Summaries are generated and may contain mistakes; the official description above is the record.