# CVE-2026-90219: RDMA/cxgb4: Free debugfs on registration failure

> A memory leak in the Linux kernel RDMA driver can lead to resource exhaustion and denial of service when device registration fails.

- **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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102623, BELL-CVE-2026-90219, DEBIAN-CVE-2026-90219, GHSA-q35c-r5m8-jm6q, UBUNTU-CVE-2026-90219

## What is CVE-2026-90219?

CVE-2026-90219 is a memory corruption vulnerability in Linux, published on 17 Sep 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:

RDMA/cxgb4: Free debugfs on registration failure

c4iw_alloc() creates the per-device debugfs tree (dev->debugfs_root via
setup_debugfs()), but it is removed only in c4iw_remove(), not in
c4iw_dealloc().  When RDMA device registration fails, the registration
worker's err_dealloc_ctx path calls c4iw_dealloc() directly, bypassing
c4iw_remove(), so the debugfs dentries leak and outlive the freed
c4iw_dev.

Move debugfs_remove_recursive() into c4iw_dealloc() so every path that
frees ctx->dev also removes its debugfs tree.

## Which versions are affected by CVE-2026-90219?


## How do I fix CVE-2026-90219?

Apply the vendor's patch.

## Is CVE-2026-90219 being exploited?

There is no known exploitation of CVE-2026-90219 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90219 and fix it if it is affected.

What it is: CVE-2026-90219 is a memory corruption vulnerability in Linux, published on 17 Sep 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-2026-90219 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-2026-90219/ (Markdown: https://insights.sbomify.com/CVE-2026-90219/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90219
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90219
- OSV: https://osv.dev/vulnerability/CVE-2026-90219

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90219/
Summaries are generated and may contain mistakes; the official description above is the record.