# CVE-2026-93040: dmaengine: dw-edma: Serialize channel state checks

> A race condition in the Linux kernel dw-edma driver can wedge DMA channels, causing a denial of service for local attackers.

- **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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102329, BELL-CVE-2026-93040, DEBIAN-CVE-2026-93040, GHSA-3g95-h923-8hfc, UBUNTU-CVE-2026-93040

## What is CVE-2026-93040?

CVE-2026-93040 is a vulnerability in Linux, published on 17 Sep 2026. 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:

dmaengine: dw-edma: Serialize channel state checks

pause() and resume() read and update channel state without holding vc.lock,
while the interrupt handlers update the same state under it. Take the same
lock around those state checks so that request, status, and configured stay
consistent.

For example, pause() can observe EDMA_ST_BUSY right before the interrupt
handler completes the final descriptor and moves the channel to
EDMA_ST_IDLE, and then record EDMA_REQ_PAUSE on an already idle channel. No
further interrupt will acknowledge the request, and since issue_pending()
requires EDMA_REQ_NONE, the channel is wedged for good: terminate_all()
leaves the stale request behind, so even reconfiguring the channel does not
recover it.

issue_pending() already runs under vc.lock, but it tests configured before
taking it. Move that test under the lock as well, so configured, request,
and status are evaluated as one channel-state snapshot.

## Which versions are affected by CVE-2026-93040?


## How do I fix CVE-2026-93040?

Apply the vendor's patch.

## Is CVE-2026-93040 being exploited?

There is no known exploitation of CVE-2026-93040 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93040 and fix it if it is affected.

What it is: CVE-2026-93040 is a vulnerability in Linux, published on 17 Sep 2026. 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-2026-93040 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-2026-93040/ (Markdown: https://insights.sbomify.com/CVE-2026-93040/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93040
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93040
- OSV: https://osv.dev/vulnerability/CVE-2026-93040

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93040/
Summaries are generated and may contain mistakes; the official description above is the record.