# CVE-2025-40224: hwmon: (cgbc-hwmon) Add missing NULL check after devm_kzalloc()

> A missing NULL check in the cgbc-hwmon driver can cause a kernel crash upon memory allocation failure, leading to denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Not stated
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-40224, DEBIAN-CVE-2025-40224, GHSA-gw2c-4fx4-rq5x, UBUNTU-CVE-2025-40224

## What is CVE-2025-40224?

CVE-2025-40224 is a vulnerability in Linux, published on 4 Dec 2025. 

### Official description

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

hwmon: (cgbc-hwmon) Add missing NULL check after devm_kzalloc()

The driver allocates memory for sensor data using devm_kzalloc(), but
did not check if the allocation succeeded. In case of memory allocation
failure, dereferencing the NULL pointer would lead to a kernel crash.

Add a NULL pointer check and return -ENOMEM to handle allocation failure
properly.

## Which versions are affected by CVE-2025-40224?


## How do I fix CVE-2025-40224?

Apply the vendor's patch.

## Is CVE-2025-40224 being exploited?

There is no known exploitation of CVE-2025-40224 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40224 and fix it if it is affected.

What it is: CVE-2025-40224 is a vulnerability in Linux, published on 4 Dec 2025. 
Exploitation: There is no known exploitation of CVE-2025-40224 in the wild and no public exploit code.

Affected product: Linux. 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-2025-40224/ (Markdown: https://insights.sbomify.com/CVE-2025-40224/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40224
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40224
- OSV: https://osv.dev/vulnerability/CVE-2025-40224

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40224/
Summaries are generated and may contain mistakes; the official description above is the record.