# CVE-2026-68216: media: pwc: Return queued buffers on start_streaming() failure

> A memory leak in the Linux kernel pwc driver allows attackers to cause denial of service by triggering start_streaming failures.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Aug 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-68216, DEBIAN-CVE-2026-68216, GHSA-3p7c-r2j9-9rqv, UBUNTU-CVE-2026-68216

## What is CVE-2026-68216?

CVE-2026-68216 is a high-severity memory corruption vulnerability in Linux, published on 10 Aug 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:

media: pwc: Return queued buffers on start_streaming() failure

The vb2 framework hands buffers to the driver via buf_queue() before
calling start_streaming().  If start_streaming() returns an error
without first returning those buffers via vb2_buffer_done(),
vb2_start_streaming() fires WARN_ON(owned_by_drv_count) and the queued
buffers leak.

pwc's start_streaming() had two early returns that hit this trap:
-ENODEV when the USB device was already disconnected, and -ERESTARTSYS
when mutex_lock_interruptible() was interrupted by a signal.  Call the
existing pwc_cleanup_queued_bufs() helper with VB2_BUF_STATE_QUEUED
before returning (matching the state already used by the
pwc_isoc_init() error path in the same function).

This mirrors the uvcvideo fix in commit 4cf3b6fd54eb ("media: uvcvideo:
Return queued buffers on start_streaming() failure").

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-68216?


## How do I fix CVE-2026-68216?

Apply the vendor's patch.

## Is CVE-2026-68216 being exploited?

There is no known exploitation of CVE-2026-68216 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68216 and fix it if it is affected.

What it is: CVE-2026-68216 is a high-severity memory corruption vulnerability in Linux, published on 10 Aug 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-2026-68216 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-2026-68216/ (Markdown: https://insights.sbomify.com/CVE-2026-68216/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68216
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68216
- OSV: https://osv.dev/vulnerability/CVE-2026-68216

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68216/
Summaries are generated and may contain mistakes; the official description above is the record.