# CVE-2025-40343: nvmet-fc: avoid scheduling association deletion twice

> A race condition in the Linux kernel nvmet-fc driver allows double scheduling of association deletion, potentially causing a denial of service.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Dec 2025
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2025-40343, DEBIAN-CVE-2025-40343, GHSA-247j-3qhv-rpc8, ROOT-OS-DEBIAN-11-CVE-2025-40343, ROOT-OS-DEBIAN-12-CVE-2025-40343, ROOT-OS-DEBIAN-13-CVE-2025-40343, ROOT-OS-UBUNTU-2204-CVE-2025-40343, ROOT-OS-UBUNTU-2404-CVE-2025-40343, UBUNTU-CVE-2025-40343

## What is CVE-2025-40343?

CVE-2025-40343 is a critical vulnerability in Linux, published on 9 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

nvmet-fc: avoid scheduling association deletion twice

When forcefully shutting down a port via the configfs interface,
nvmet_port_subsys_drop_link() first calls nvmet_port_del_ctrls() and
then nvmet_disable_port(). Both functions will eventually schedule all
remaining associations for deletion.

The current implementation checks whether an association is about to be
removed, but only after the work item has already been scheduled. As a
result, it is possible for the first scheduled work item to free all
resources, and then for the same work item to be scheduled again for
deletion.

Because the association list is an RCU list, it is not possible to take
a lock and remove the list entry directly, so it cannot be looked up
again. Instead, a flag (terminating) must be used to determine whether
the association is already in the process of being deleted.

## Which versions are affected by CVE-2025-40343?


## How do I fix CVE-2025-40343?

Apply the vendor's patch.

## Is CVE-2025-40343 being exploited?

There is no known exploitation of CVE-2025-40343 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40343 and fix it if it is affected.

What it is: CVE-2025-40343 is a critical vulnerability in Linux, published on 9 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-40343 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-2025-40343/ (Markdown: https://insights.sbomify.com/CVE-2025-40343/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40343
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40343
- OSV: https://osv.dev/vulnerability/CVE-2025-40343

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40343/
Summaries are generated and may contain mistakes; the official description above is the record.