# CVE-2026-68416: mtd: fix double free and WARN_ON in add_mtd_device() error paths

> A double free vulnerability in the Linux kernel MTD subsystem allows local attackers to cause a denial of service or potentially execute arbitrary code.

- **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:** 10 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-68416, DEBIAN-CVE-2026-68416, GHSA-qpvq-4872-pr63, UBUNTU-CVE-2026-68416

## What is CVE-2026-68416?

CVE-2026-68416 is an use after free vulnerability in Linux, published on 10 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:

mtd: fix double free and WARN_ON in add_mtd_device() error paths

When device_register() or mtd_nvmem_add() fails inside
add_mtd_device() for a partition, the error handling triggers
mtd_release() via put_device() or device_unregister(). mtd_release()
calls release_mtd_partition() which frees the mtd_info structure.
However, callers such as mtd_add_partition() and add_mtd_partitions()
also call free_partition() in their error paths, resulting in a double
free.

Additionally, release_mtd_partition() hits WARN_ON(!list_empty(
&mtd->part.node)) because the partition node is still linked in the
parent's partitions list when the release callback fires from the
add_mtd_device() error path.

Fix this by overriding dev->type and dev->release before put_device()
in the error paths, so that device_release() invokes a no-op function
instead of mtd_release(). For the mtd_nvmem_add() failure case,
device_unregister() is replaced with device_del() to separate the
device removal from the final kobject reference drop, allowing the
override to take effect before put_device() is called.

The callers' error paths (list_del + free_partition) remain the sole
owners of mtd_info lifetime on add_mtd_device() failure, which is the
expected contract.

The normal partition teardown path is not affected: del_mtd_device()
goes through kref_put() -> mtd_device_release() -> device_unregister()
with dev->type still set to &mtd_devtype, so mtd_release() ->
release_mtd_partition() continues to work correctly for the regular
removal case.

## Which versions are affected by CVE-2026-68416?


## How do I fix CVE-2026-68416?

Apply the vendor's patch.

## Is CVE-2026-68416 being exploited?

There is no known exploitation of CVE-2026-68416 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68416 and fix it if it is affected.

What it is: CVE-2026-68416 is an use after free vulnerability in Linux, published on 10 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-2026-68416 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-2026-68416/ (Markdown: https://insights.sbomify.com/CVE-2026-68416/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68416
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68416
- OSV: https://osv.dev/vulnerability/CVE-2026-68416

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68416/
Summaries are generated and may contain mistakes; the official description above is the record.