---
id: "CVE-2026-98689"
kind: "vulnerability"
aliases: ["CVE-2026-98689"]
title: "Linux kernel: Thunderbolt DP tunnel accessed after teardown, causing use-after-free"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["laptops", "linux-kernel", "runtime", "thunderbolt"]
not_affected_if: ["no-thunderbolt-hardware"]
published_at: "2026-10-18T16:17:22+00:00"
first_seen_at: "2026-10-23T21:57:16+00:00"
updated_at: "2026-10-25T05:19:05+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98689", "first_seen_at": "2026-10-23T21:57:16+00:00"}]
---

# Linux kernel: Thunderbolt DP tunnel accessed after teardown, causing use-after-free

A race in the Linux kernel Thunderbolt driver lets a DisplayPort tunnel be accessed after its DPRX read was cancelled during suspend or shutdown. The sources do not state the exact effect beyond this access to a torn-down tunnel.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- unknown

## Timeline

- 2026-10-23T21:57:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98689

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

thunderbolt: Don't access a DP tunnel after its DPRX read was canceled

tb_dp_dprx_work() checks ->dprx_canceled before it takes tb->lock so it
misses a tb_dp_dprx_stop() that could not cancel the already running
work. It then polls the DPRX capabilities and runs the callback for a
tunnel that has already been torn down while the domain is suspending or
going away.

This can be hit by cancelling the DPRX read from outside the ordered
tb->wq: During suspend tb_disconnect_and_release_dp() does just this and
with a later patch tb_stop() will do it as well. The latter in combination
with the Apple NHI where the DPRX read never completed is how I hit
this.

Check the flag with tb->lock held instead and check it again in
tb_dp_tunnel_active() because the callback runs after the lock has been
dropped again.

Also clear the flag in tb_dp_dprx_start() so that it only ever describes
the work that is currently in flight.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_