# CVE-2025-40342: nvme-fc: use lock accessing port_state and rport state

> A race condition in the Linux kernel NVMe FC driver allows attackers to cause a denial of service by triggering concurrent unregister and reconnect operations.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 9 Dec 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2025-40342, DEBIAN-CVE-2025-40342, GHSA-gvgm-wg7j-vj8f, ROOT-OS-DEBIAN-12-CVE-2025-40342, ROOT-OS-DEBIAN-13-CVE-2025-40342, ROOT-OS-UBUNTU-2204-CVE-2025-40342, ROOT-OS-UBUNTU-2404-CVE-2025-40342, UBUNTU-CVE-2025-40342

## What is CVE-2025-40342?

CVE-2025-40342 is a high-severity vulnerability in Linux, published on 9 Dec 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:

nvme-fc: use lock accessing port_state and rport state

nvme_fc_unregister_remote removes the remote port on a lport object at
any point in time when there is no active association. This races with
with the reconnect logic, because nvme_fc_create_association is not
taking a lock to check the port_state and atomically increase the
active count on the rport.

## Which versions are affected by CVE-2025-40342?


## How do I fix CVE-2025-40342?

Apply the vendor's patch.

## Is CVE-2025-40342 being exploited?

There is no known exploitation of CVE-2025-40342 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40342 and fix it if it is affected.

What it is: CVE-2025-40342 is a high-severity vulnerability in Linux, published on 9 Dec 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-2025-40342 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-2025-40342/ (Markdown: https://insights.sbomify.com/CVE-2025-40342/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40342
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40342
- OSV: https://osv.dev/vulnerability/CVE-2025-40342

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40342/
Summaries are generated and may contain mistakes; the official description above is the record.