# CVE-2025-68298: Bluetooth: btusb: mediatek: Avoid btusb_mtk_claim_iso_intf() NULL deref

> A NULL pointer dereference in the Linux kernel Bluetooth driver allows local attackers to cause a system crash via specific USB interactions.

- **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:** 16 Dec 2025
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2025-68298, DEBIAN-CVE-2025-68298, GHSA-f9r4-fv84-3cgc, UBUNTU-CVE-2025-68298

## What is CVE-2025-68298?

CVE-2025-68298 is a vulnerability in Linux, published on 16 Dec 2025. 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: btusb: mediatek: Avoid btusb_mtk_claim_iso_intf() NULL deref

In btusb_mtk_setup(), we set `btmtk_data->isopkt_intf` to:
  usb_ifnum_to_if(data->udev, MTK_ISO_IFNUM)

That function can return NULL in some cases. Even when it returns
NULL, though, we still go on to call btusb_mtk_claim_iso_intf().

As of commit e9087e828827 ("Bluetooth: btusb: mediatek: Add locks for
usb_driver_claim_interface()"), calling btusb_mtk_claim_iso_intf()
when `btmtk_data->isopkt_intf` is NULL will cause a crash because
we'll end up passing a bad pointer to device_lock(). Prior to that
commit we'd pass the NULL pointer directly to
usb_driver_claim_interface() which would detect it and return an
error, which was handled.

Resolve the crash in btusb_mtk_claim_iso_intf() by adding a NULL check
at the start of the function. This makes the code handle a NULL
`btmtk_data->isopkt_intf` the same way it did before the problematic
commit (just with a slight change to the error message printed).

## Which versions are affected by CVE-2025-68298?


## How do I fix CVE-2025-68298?

Apply the vendor's patch.

## Is CVE-2025-68298 being exploited?

There is no known exploitation of CVE-2025-68298 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68298 and fix it if it is affected.

What it is: CVE-2025-68298 is a vulnerability in Linux, published on 16 Dec 2025. 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-2025-68298 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-2025-68298/ (Markdown: https://insights.sbomify.com/CVE-2025-68298/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68298
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68298
- OSV: https://osv.dev/vulnerability/CVE-2025-68298

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68298/
Summaries are generated and may contain mistakes; the official description above is the record.