# CVE-2026-93042: dmaengine: dw-edma: Terminate all descriptors without callbacks

> A use-after-free vulnerability in the Linux kernel dw-edma driver allows attackers to execute code or cause denial of service via improper descriptor termination.

- **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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-101988, BELL-CVE-2026-93042, DEBIAN-CVE-2026-93042, GHSA-m4jg-4gfw-gm5r, UBUNTU-CVE-2026-93042

## What is CVE-2026-93042?

CVE-2026-93042 is a high-severity use after free 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: Terminate all descriptors without callbacks

The DMA Engine client documentation says in the "Terminate APIs" section
of Documentation/driver-api/dmaengine/client.rst:

"No callback functions will be called for any incomplete transfers."

dw-edma instead calls vchan_cookie_complete() when a deferred STOP reaches
the interrupt handler. This schedules a callback for the active descriptor
and leaves other issued or submitted descriptors queued. A late callback
after dmaengine_terminate_sync() can dereference client state that has
already been freed, while leftover descriptors may later restart into
reused buffers or leak.

Move all issued and submitted descriptors to the terminated list whenever
termination completes. For a pending STOP, do this from both the DONE and
ABORT paths. Complete their cookies in order without scheduling callbacks.

A STOP can remain pending until the running transfer raises an
interrupt. Make device_synchronize() wait for such a pending STOP to
complete before releasing terminated descriptors. Reuse it from
free_chan_resources(), then release the remaining virt-dma resources.
Sleep instead of busy-polling while waiting, and warn if the existing
timeout expires.

## Which versions are affected by CVE-2026-93042?


## How do I fix CVE-2026-93042?

Apply the vendor's patch.

## Is CVE-2026-93042 being exploited?

There is no known exploitation of CVE-2026-93042 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93042 and fix it if it is affected.

What it is: CVE-2026-93042 is a high-severity use after free 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-2026-93042 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-2026-93042/ (Markdown: https://insights.sbomify.com/CVE-2026-93042/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93042
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93042
- OSV: https://osv.dev/vulnerability/CVE-2026-93042

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93042/
Summaries are generated and may contain mistakes; the official description above is the record.