# CVE-2026-90158: m68k: nfcon: Do not call console_is_registered() in nfcon_device()

> A deadlock in the Linux kernel m68k nfcon driver causes a denial of service when console registration functions are called concurrently.

- **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-102012, BELL-CVE-2026-90158, DEBIAN-CVE-2026-90158, GHSA-fwv7-hfpv-34gj, UBUNTU-CVE-2026-90158

## What is CVE-2026-90158?

CVE-2026-90158 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:

m68k: nfcon: Do not call console_is_registered() in nfcon_device()

Since 7c2af0f634f1 ("tty: tty_io: use console_list_lock for list
synchronization") show_cons_active() calls the .device() method under
the console_list_lock, but console_is_registered() tries to acquire
console_list_lock as well, causing a deadlock.  It should not be
necessary to check console_is_registered() here since the function
should not be called in the fist place when the console is not
registered.

## Which versions are affected by CVE-2026-90158?


## How do I fix CVE-2026-90158?

Apply the vendor's patch.

## Is CVE-2026-90158 being exploited?

There is no known exploitation of CVE-2026-90158 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90158 and fix it if it is affected.

What it is: CVE-2026-90158 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-2026-90158 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-2026-90158/ (Markdown: https://insights.sbomify.com/CVE-2026-90158/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90158
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90158
- OSV: https://osv.dev/vulnerability/CVE-2026-90158

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90158/
Summaries are generated and may contain mistakes; the official description above is the record.