# CVE-2025-40121: ASoC: Intel: bytcr_rt5651: Fix invalid quirk input mapping

> A local attacker with high privileges can trigger out-of-bounds memory access in the Intel bytcr_rt5651 audio driver by passing invalid quirk options, potentially leading to code execution or system crash.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Nov 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-40121, DEBIAN-CVE-2025-40121, GHSA-7q66-w47h-g677, ROOT-OS-DEBIAN-11-CVE-2025-40121, ROOT-OS-DEBIAN-13-CVE-2025-40121, ROOT-OS-UBUNTU-2404-CVE-2025-40121, UBUNTU-CVE-2025-40121

## What is CVE-2025-40121?

CVE-2025-40121 is a memory corruption vulnerability in Linux, published on 12 Nov 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:

ASoC: Intel: bytcr_rt5651: Fix invalid quirk input mapping

When an invalid value is passed via quirk option, currently
bytcr_rt5640 driver just ignores and leaves as is, which may lead to
unepxected results like OOB access.

This patch adds the sanity check and corrects the input mapping to the
certain default value if an invalid value is passed.

## Which versions are affected by CVE-2025-40121?


## How do I fix CVE-2025-40121?

Apply the vendor's patch.

## Is CVE-2025-40121 being exploited?

There is no known exploitation of CVE-2025-40121 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40121 and fix it if it is affected.

What it is: CVE-2025-40121 is a memory corruption vulnerability in Linux, published on 12 Nov 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-2025-40121 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-2025-40121/ (Markdown: https://insights.sbomify.com/CVE-2025-40121/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40121
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40121
- OSV: https://osv.dev/vulnerability/CVE-2025-40121

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40121/
Summaries are generated and may contain mistakes; the official description above is the record.