# CVE-2026-97516: wifi: rtw88: Add NULL check for chip->edcca_th in rtw_fw_adaptivity_result()

> A missing NULL check in the rtw88 WiFi driver causes a kernel oops when processing adaptivity results on specific chips, leading to denial of service.

- **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:** 24 Sep 2026
- **Updated:** 3 Oct 2026
- **Also known as:** AZL-103733, BELL-CVE-2026-97516, DEBIAN-CVE-2026-97516, GHSA-4jwf-r7m6-8rg5, UBUNTU-CVE-2026-97516

## What is CVE-2026-97516?

CVE-2026-97516 is a vulnerability in Linux, published on 24 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: rtw88: Add NULL check for chip->edcca_th in rtw_fw_adaptivity_result()

It was recently reported that rtw_fw_adaptivity_result()
in fw.c dereferences rtwdev->chip->edcca_th without
a NULL check. The issue is that devices with the
8821CE chip don't define edcca_th in their chip
info. As a result, when rtw_fw_adaptivity_result()
tries to dereference it, the kernel triggers an oops.

Add a NULL check for edcca_th before dereferencing
it in rtw_fw_adaptivity_result() in fw.c. Placing
the check at the function entry avoids logging any
garbage values.

This change does not address the root cause for
this behavior, but it prevents the NULL dereference
and the resulting oops while a more permanent solution
is developed.

Tested on a 8822CE chip which defines edcca_th, so
this issue is not present on it, but it still uses
this driver and I can verify there are no regressions.

## Which versions are affected by CVE-2026-97516?


## How do I fix CVE-2026-97516?

Apply the vendor's patch.

## Is CVE-2026-97516 being exploited?

There is no known exploitation of CVE-2026-97516 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97516 and fix it if it is affected.

What it is: CVE-2026-97516 is a vulnerability in Linux, published on 24 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-2026-97516 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-2026-97516/ (Markdown: https://insights.sbomify.com/CVE-2026-97516/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97516
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97516
- OSV: https://osv.dev/vulnerability/CVE-2026-97516

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97516/
Summaries are generated and may contain mistakes; the official description above is the record.