# CVE-2026-68213: media: rtl2832_sdr: Return queued buffers on start_streaming() failure

> A bug in the rtl2832_sdr driver causes buffer leaks and warnings when streaming fails, potentially leading to resource exhaustion or system instability.

- **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-2026-68213, DEBIAN-CVE-2026-68213, GHSA-rjmw-6r45-2xm2, UBUNTU-CVE-2026-68213

## What is CVE-2026-68213?

CVE-2026-68213 is a high-severity denial of service 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: rtl2832_sdr: 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.

rtl2832_sdr_start_streaming() had multiple error paths that hit this
trap: two direct early returns (-ENODEV, -ERESTARTSYS), plus six
`goto err` paths covering subdev s_power, tuner setup, ADC setup,
stream-buffer allocation, urb allocation, and urb submission failures.
None of them returned the queued buffers.

The original function had no distinct success exit and fell straight
through into the err label, which previously only did mutex_unlock and
"return ret".  Adding queued-buffer cleanup at err must therefore be
paired with an explicit success return; otherwise every successful
start would also drain the buffer queue and kill streaming.  Add that
success return, then add rtl2832_sdr_cleanup_queued_bufs() at the err
label and before each early return.

The cleanup helper takes a vb2_buffer_state argument so that the
start_streaming error paths can pass VB2_BUF_STATE_QUEUED (as
expected by userspace on start_streaming failure) while stop_streaming
keeps its existing VB2_BUF_STATE_ERROR semantics.

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

The err label still does not roll back power_ctrl(), frontend_ctrl(),
the POWER_ON flag, or stream/URB allocations that may have happened
before the failing step.  Those are pre-existing leaks of a different
class and are not addressed here.

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

## Which versions are affected by CVE-2026-68213?


## How do I fix CVE-2026-68213?

Apply the vendor's patch.

## Is CVE-2026-68213 being exploited?

There is no known exploitation of CVE-2026-68213 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68213 and fix it if it is affected.

What it is: CVE-2026-68213 is a high-severity denial of service 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-2026-68213 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-2026-68213/ (Markdown: https://insights.sbomify.com/CVE-2026-68213/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68213
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68213
- OSV: https://osv.dev/vulnerability/CVE-2026-68213

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68213/
Summaries are generated and may contain mistakes; the official description above is the record.