# CVE-2026-98342: dmaengine: wait for RCU readers before releasing dma_device

> A use-after-free in the Linux kernel DMA engine allows local attackers to cause denial of service or execute code via race conditions during device release.

- **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:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-106005, BELL-CVE-2026-98342, DEBIAN-CVE-2026-98342, GHSA-jvjw-jpr2-5gjp, UBUNTU-CVE-2026-98342

## What is CVE-2026-98342?

CVE-2026-98342 is an use after free vulnerability in Linux, published on 6 Oct 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: wait for RCU readers before releasing dma_device

dma_issue_pending_all() walks the dma_device_list with
list_for_each_entry_rcu() under rcu_read_lock(). dma_device_release()
unlinks the device with list_del_rcu() and then calls
device->device_release() (which in many drivers, such as plx_dma.c,
directly calls kfree()).

Because there is no grace period between unlinking the device and
freeing it, concurrent RCU readers in dma_issue_pending_all() can
access the device after it has been freed.

The lockless walk originally relied on clients holding a dmaengine
reference to pin the provider module, and therefore the device, for as
long as they might traverse the list. Commit 8ad342a86359 ("dmaengine:
Add reference counting to dma_device struct") decoupled the dma_device
lifetime from the module reference, so the device can now be released
while a reader is still walking the list.

Add synchronize_rcu() before the device is freed, so RCU readers are
guaranteed to have finished. Keep it unconditional: providers that do
not implement device_release() free the device themselves once
dma_async_device_unregister() returns. This call will delay for a grace
period with dma_list_mutex held, which is safe and only teardown path is
delayed.

## Which versions are affected by CVE-2026-98342?


## How do I fix CVE-2026-98342?

Apply the vendor's patch.

## Is CVE-2026-98342 being exploited?

There is no known exploitation of CVE-2026-98342 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98342 and fix it if it is affected.

What it is: CVE-2026-98342 is an use after free vulnerability in Linux, published on 6 Oct 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-2026-98342 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-2026-98342/ (Markdown: https://insights.sbomify.com/CVE-2026-98342/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98342
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98342
- OSV: https://osv.dev/vulnerability/CVE-2026-98342

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98342/
Summaries are generated and may contain mistakes; the official description above is the record.