# CVE-2026-64478: ALSA: usb-audio: avoid kobject path lookup in DualSense match

> A race condition in the Linux kernel ALSA USB audio driver causes a null pointer dereference during rapid DualSense controller hotplugging, leading to a system crash.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 25 Jul 2026
- **Updated:** 17 Aug 2026
- **Also known as:** AZL-93728, BELL-CVE-2026-64478, DEBIAN-CVE-2026-64478, GHSA-wv3c-4j75-q9c9, ROOT-OS-UBUNTU-2204-CVE-2026-64478, UBUNTU-CVE-2026-64478

## What is CVE-2026-64478?

CVE-2026-64478 is a vulnerability in Linux, published on 25 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

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

ALSA: usb-audio: avoid kobject path lookup in DualSense match

The DualSense jack-detection input handler verifies that a matching input
device belongs to the same physical controller by building kobject path
strings for both the input device and the USB audio device, then comparing
the path prefix.

This was observed when a weak physical connection caused the controller
to rapidly disconnect and reconnect. During that repeated hotplug,
snd_dualsense_ih_match() can run while the controller's USB device is
being disconnected. kobject_get_path() walks ancestor kobjects and
dereferences their names; if the USB device kobject name is no longer
valid, this can fault in strlen():

  RIP: 0010:strlen+0x10/0x30
  Call Trace:
   kobject_get_path+0x34/0x150
   snd_dualsense_ih_match+0x49/0xd0 [snd_usb_audio]
   input_register_device+0x566/0x6a0
   ps_probe+0xb89/0x1590 [hid_playstation]

The same ownership check can be done without building kobject path
strings. The input device is parented below the HID device, USB interface
and USB device, so walking the input device parent chain and comparing
against the mixer USB device preserves the check without dereferencing
kobject names during disconnect.

## Which versions are affected by CVE-2026-64478?


## How do I fix CVE-2026-64478?

Apply the vendor's patch.

## Is CVE-2026-64478 being exploited?

There is no known exploitation of CVE-2026-64478 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64478 and fix it if it is affected.

What it is: CVE-2026-64478 is a vulnerability in Linux, published on 25 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-64478 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-2026-64478/ (Markdown: https://insights.sbomify.com/CVE-2026-64478/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64478
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64478
- OSV: https://osv.dev/vulnerability/CVE-2026-64478

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64478/
Summaries are generated and may contain mistakes; the official description above is the record.