# CVE-2026-80698: dmaengine: idxd: fix double free of wq, engine, and group structs

> A double free vulnerability in the Linux kernel idxd driver allows local attackers to cause denial of service or potentially escalate privileges.

- **Severity:** Not scored
- **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:** 28 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-98153, BELL-CVE-2026-80698, DEBIAN-CVE-2026-80698, GHSA-5mr4-5v55-qp75, UBUNTU-CVE-2026-80698

## What is CVE-2026-80698?

CVE-2026-80698 is an use after free vulnerability in Linux, published on 28 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 double free of wq, engine, and group structs

The release callbacks for wq, engine, and group devices
(idxd_conf_wq_release, idxd_conf_engine_release,
idxd_conf_group_release) each call kfree() on the enclosing struct.
The setup error paths and cleanup functions also call kfree()
explicitly after put_device(), producing a double free whenever
put_device() drops the reference count to zero and fires the release.

In the setup functions, device_initialize() is called before
device_add(), so the reference count is exactly 1 at the error sites.
put_device() unconditionally fires the release, which frees the struct;
the subsequent explicit kfree() then operates on freed memory.

For idxd_setup_wqs(), the wq release callback also owns opcap_bmap
and wqcfg. The error unwind additionally freed those fields explicitly
before calling put_device(), causing further double frees on both.

Remove the redundant explicit kfree() calls from all setup error paths
and cleanup functions for wq, engine, and group structs, delegating
sole ownership of those allocations to the release callbacks.

## Which versions are affected by CVE-2026-80698?


## How do I fix CVE-2026-80698?

Apply the vendor's patch.

## Is CVE-2026-80698 being exploited?

There is no known exploitation of CVE-2026-80698 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80698 and fix it if it is affected.

What it is: CVE-2026-80698 is an use after free vulnerability in Linux, published on 28 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-2026-80698 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-2026-80698/ (Markdown: https://insights.sbomify.com/CVE-2026-80698/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80698
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80698
- OSV: https://osv.dev/vulnerability/CVE-2026-80698

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80698/
Summaries are generated and may contain mistakes; the official description above is the record.