# CVE-2026-98217: IB/mlx4: Fix use-after-free on pkey sysfs registration failure

> A use-after-free in the Linux kernel mlx4 InfiniBand driver allows local attackers to cause a system crash or potentially execute code via device cleanup.

- **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-106071, BELL-CVE-2026-98217, DEBIAN-CVE-2026-98217, GHSA-pc9g-8wgv-jv4j, UBUNTU-CVE-2026-98217

## What is CVE-2026-98217?

CVE-2026-98217 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:

IB/mlx4: Fix use-after-free on pkey sysfs registration failure

register_pkey_tree() ignores errors from register_one_pkey_tree() and
continues registering the remaining slaves. The per-slave error path has
already released the pkey parent kobjects, but their pointers remain
stored in the device. A later device cleanup therefore passes the stale
pointers to kobject_put(), causing a use-after-free.

Clear the parent pointers after releasing a failed slave tree and skip
unregistered trees during device cleanup. This preserves the existing
best-effort registration behavior while preventing a second cleanup of
the failed tree.

## Which versions are affected by CVE-2026-98217?


## How do I fix CVE-2026-98217?

Apply the vendor's patch.

## Is CVE-2026-98217 being exploited?

There is no known exploitation of CVE-2026-98217 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98217 and fix it if it is affected.

What it is: CVE-2026-98217 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-2026-98217 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-2026-98217/ (Markdown: https://insights.sbomify.com/CVE-2026-98217/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98217
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98217
- OSV: https://osv.dev/vulnerability/CVE-2026-98217

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98217/
Summaries are generated and may contain mistakes; the official description above is the record.