# CVE-2026-98692: thunderbolt: Make the DP tunnel activation callback mandatory

> A reference leak in the Linux kernel Thunderbolt driver can cause memory exhaustion and denial of service during hibernation restore.

- **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:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-98692, DEBIAN-CVE-2026-98692, GHSA-j976-jwv6-gqm2, UBUNTU-CVE-2026-98692

## What is CVE-2026-98692?

CVE-2026-98692 is a memory corruption vulnerability in Linux, published on 18 Oct 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:

thunderbolt: Make the DP tunnel activation callback mandatory

tb_tunnel_alloc_dp() takes an optional callback which is run from
dprx_work once the DPRX capabilities read has completed. Without that
callback tb_dp_dprx_start() reads the capabilities synchronously and
never queues the work. It however always takes a tunnel reference which
is only dropped by dprx_work itself or by tb_dp_dprx_stop() when
cancel_delayed_work() actually canceled that work. That reference is
thus leaked for every tunnel without a callback.

The only tunnels without one are those from tb_tunnel_discover_dp(),
which are activated again when restoring from hibernation.
Pass the callback to tb_tunnel_discover_dp() as well and drop the
synchronous path such that the DPRX capabilities are always read from
dprx_work. Hibernation restore then also no longer blocks for up to 12
seconds while waiting for that read to complete.

Also fix up the KUnit tests.

## Which versions are affected by CVE-2026-98692?


## How do I fix CVE-2026-98692?

Apply the vendor's patch.

## Is CVE-2026-98692 being exploited?

There is no known exploitation of CVE-2026-98692 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98692 and fix it if it is affected.

What it is: CVE-2026-98692 is a memory corruption vulnerability in Linux, published on 18 Oct 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-2026-98692 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-2026-98692/ (Markdown: https://insights.sbomify.com/CVE-2026-98692/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98692
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98692
- OSV: https://osv.dev/vulnerability/CVE-2026-98692

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98692/
Summaries are generated and may contain mistakes; the official description above is the record.