# CVE-2026-93149: wifi: mac80211_hwsim: avoid NULL skb in stop queue drain

> A race condition in the Linux kernel's mac80211_hwsim driver can cause a NULL pointer dereference, leading to a system crash.

- **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-102957, BELL-CVE-2026-93149, DEBIAN-CVE-2026-93149, GHSA-9v89-8pp7-7fmp, UBUNTU-CVE-2026-93149

## What is CVE-2026-93149?

CVE-2026-93149 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:

wifi: mac80211_hwsim: avoid NULL skb in stop queue drain

mac80211_hwsim_stop() drops any frames left in data->pending. The loop
currently checks skb_queue_empty() and then dequeues separately.

That split is racy with TX status handling, which can remove a pending
frame under the queue lock. If the last entry is removed after the empty
check, skb_dequeue() returns NULL and the stop path passes that NULL skb
to ieee80211_free_txskb().

Use skb_dequeue() as the loop condition instead. The dequeue result is the
object that stop owns and frees, and a concurrent status completion that
empties the queue simply makes the loop terminate.

## Which versions are affected by CVE-2026-93149?


## How do I fix CVE-2026-93149?

Apply the vendor's patch.

## Is CVE-2026-93149 being exploited?

There is no known exploitation of CVE-2026-93149 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93149 and fix it if it is affected.

What it is: CVE-2026-93149 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-2026-93149 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-2026-93149/ (Markdown: https://insights.sbomify.com/CVE-2026-93149/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93149
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93149
- OSV: https://osv.dev/vulnerability/CVE-2026-93149

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93149/
Summaries are generated and may contain mistakes; the official description above is the record.