# CVE-2026-74574: dmaengine: idxd: fix fdev setup failure cleanup in idxd_cdev_open()

> A race condition in the Linux kernel idxd driver causes a deadlock and use-after-free during device open failures, leading to system denial of service.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-74574, DEBIAN-CVE-2026-74574, GHSA-6vf2-r72r-2pc8, UBUNTU-CVE-2026-74574

## What is CVE-2026-74574?

CVE-2026-74574 is a high-severity vulnerability in Linux, published on 15 Aug 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: idxd: fix fdev setup failure cleanup in idxd_cdev_open()

The failed_dev_add and failed_dev_name paths drop the file-device
reference while wq->wq_lock is still held. If put_device(fdev) drops the
last reference, idxd_file_dev_release() runs synchronously and tries to
take wq->wq_lock again, deadlocking.

Those paths also fall through into the later ctx cleanup labels even
though idxd_file_dev_release() owns that cleanup and frees ctx. This can
make idxd_xa_pasid_remove(ctx) and kfree(ctx) operate on a freed context.

Move idxd_wq_get() before file-device setup can fail, since the release
callback always calls idxd_wq_put(). Then unlock wq->wq_lock before
put_device(fdev) and return directly from the file-device setup failure
path, leaving ctx cleanup to the release callback.

## Which versions are affected by CVE-2026-74574?


## How do I fix CVE-2026-74574?

Apply the vendor's patch.

## Is CVE-2026-74574 being exploited?

There is no known exploitation of CVE-2026-74574 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74574 and fix it if it is affected.

What it is: CVE-2026-74574 is a high-severity vulnerability in Linux, published on 15 Aug 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-2026-74574 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-2026-74574/ (Markdown: https://insights.sbomify.com/CVE-2026-74574/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74574
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74574
- OSV: https://osv.dev/vulnerability/CVE-2026-74574

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74574/
Summaries are generated and may contain mistakes; the official description above is the record.