# CVE-2026-90085: octeontx2-af: fix NULL deref in NIX TM tree debugfs read path

> A local attacker with debugfs access can trigger a kernel crash by reading a specific file when transmit queues are uninitialized.

- **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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-90085, DEBIAN-CVE-2026-90085, GHSA-m9hw-68r8-5833, UBUNTU-CVE-2026-90085

## What is CVE-2026-90085?

CVE-2026-90085 is a 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:

octeontx2-af: fix NULL deref in NIX TM tree debugfs read path

rvu_dbg_nix_tm_tree_display() dereferences pfvf->sq_ctx without
checking whether the SQ context has been allocated. Reading
/sys/kernel/debug/octeontx2/nix/tm_tree for a NIX LF whose transmit
queues are not set up triggers a kernel oops.

Guard the read path the same way rvu_dbg_nix_tm_tree_write() already
does and return -EINVAL with a seq_file message when sq_ctx is NULL.

## Which versions are affected by CVE-2026-90085?


## How do I fix CVE-2026-90085?

Apply the vendor's patch.

## Is CVE-2026-90085 being exploited?

There is no known exploitation of CVE-2026-90085 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90085 and fix it if it is affected.

What it is: CVE-2026-90085 is a 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-2026-90085 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-2026-90085/ (Markdown: https://insights.sbomify.com/CVE-2026-90085/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90085
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90085
- OSV: https://osv.dev/vulnerability/CVE-2026-90085

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90085/
Summaries are generated and may contain mistakes; the official description above is the record.