# CVE-2026-97908: Bluetooth: btqcomsmd: destroy RPMsg endpoints before freeing hci_dev

> A use-after-free in the Linux kernel Bluetooth driver allows attackers with Bluetooth proximity to cause crashes or execute code via race conditions during device teardown.

- **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:** 25 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-104394, BELL-CVE-2026-97908, DEBIAN-CVE-2026-97908, GHSA-rm82-grpq-rh3c, UBUNTU-CVE-2026-97908

## What is CVE-2026-97908?

CVE-2026-97908 is an use after free vulnerability in Linux, published on 25 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:

Bluetooth: btqcomsmd: destroy RPMsg endpoints before freeing hci_dev

The command and ACL RPMsg endpoints store struct btqcomsmd as their
callback private data. The receive callbacks dereference btq->hdev
without taking an hci_dev reference.

The current teardown order frees the hci_dev before destroying the RPMsg
endpoints in both the hci_register_dev() error path and the driver remove
path. If WCNSS delivers data in that window, the endpoint callback can
run with an already freed hci_dev and pass it to the Bluetooth core.

For qcom_smd endpoints, rpmsg_destroy_ept() closes the channel and clears
the callback under the channel recv_lock. The receive path holds the same
lock while invoking the callback, so destroying the endpoints first both
prevents new callbacks and serializes with any callback already running.

Destroy the command and ACL endpoints before hci_free_dev(). Keep
hci_unregister_dev() first during remove so the HCI core stops issuing
operations before the transport endpoints are shut down. In the full
registration-error cleanup path, return directly after freeing the hci_dev
to avoid falling through to the partial-construction labels and destroying
the endpoints twice.

## Which versions are affected by CVE-2026-97908?


## How do I fix CVE-2026-97908?

Apply the vendor's patch.

## Is CVE-2026-97908 being exploited?

There is no known exploitation of CVE-2026-97908 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97908 and fix it if it is affected.

What it is: CVE-2026-97908 is an use after free vulnerability in Linux, published on 25 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-2026-97908 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-2026-97908/ (Markdown: https://insights.sbomify.com/CVE-2026-97908/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97908
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97908
- OSV: https://osv.dev/vulnerability/CVE-2026-97908

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97908/
Summaries are generated and may contain mistakes; the official description above is the record.