# CVE-2025-40062: crypto: hisilicon/qm - set NULL to qm->debug.qm_diff_regs

> A double free vulnerability in the Linux kernel Hisilicon QM driver can cause a system crash during device removal if initialization fails.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Oct 2025
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2025-40062, DEBIAN-CVE-2025-40062, GHSA-8c8f-r28v-v5hp, ROOT-OS-DEBIAN-12-CVE-2025-40062, ROOT-OS-DEBIAN-13-CVE-2025-40062, ROOT-OS-UBUNTU-2404-CVE-2025-40062, UBUNTU-CVE-2025-40062

## What is CVE-2025-40062?

CVE-2025-40062 is an use after free vulnerability in Linux, published on 28 Oct 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:

crypto: hisilicon/qm - set NULL to qm->debug.qm_diff_regs

When the initialization of qm->debug.acc_diff_reg fails,
the probe process does not exit. However, after qm->debug.qm_diff_regs is
freed, it is not set to NULL. This can lead to a double free when the
remove process attempts to free it again. Therefore, qm->debug.qm_diff_regs
should be set to NULL after it is freed.

## Which versions are affected by CVE-2025-40062?


## How do I fix CVE-2025-40062?

Apply the vendor's patch.

## Is CVE-2025-40062 being exploited?

There is no known exploitation of CVE-2025-40062 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40062 and fix it if it is affected.

What it is: CVE-2025-40062 is an use after free vulnerability in Linux, published on 28 Oct 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-2025-40062 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-2025-40062/ (Markdown: https://insights.sbomify.com/CVE-2025-40062/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40062
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40062
- OSV: https://osv.dev/vulnerability/CVE-2025-40062

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40062/
Summaries are generated and may contain mistakes; the official description above is the record.