# CVE-2026-68175: tracing: Fix resource leak on mmiotrace trace_pipe close

> Local attackers with high privileges can cause a resource leak and denial of service by repeatedly opening and closing the mmiotrace trace_pipe.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Aug 2026
- **Updated:** 19 Aug 2026
- **Also known as:** BELL-CVE-2026-68175, DEBIAN-CVE-2026-68175, GHSA-frw4-mrvx-h68w, UBUNTU-CVE-2026-68175

## What is CVE-2026-68175?

CVE-2026-68175 is a 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:

tracing: Fix resource leak on mmiotrace trace_pipe close

The mmiotrace tracer was added May 12th 2008. At that time, resources
created in pipe_open() could not be freed because there was not
pipe_close function pointer of the tracer. The pipe_close function pointer
was added in December 7th, 2009, but the mmiotrace tracer was not updated.

mmio_pipe_open() allocates a header_iter and takes a pci_dev reference
when trace_pipe is opened. mmio_close() frees them, but it was only
wired to the tracer's .close callback.

tracing_release_pipe() invokes .pipe_close, not .close, when the
trace_pipe file is released. As a result, closing trace_pipe with the
mmiotrace tracer active leaked the header_iter allocation and left a
stale pci_dev reference.

Set .pipe_close to mmio_close, matching how function_graph wires both
callbacks to the same handler.

Note, if the trace_pipe is read to completion, it will clean up the
resources, but if one were to run:

  # head -n 1 /sys/kernel/tracing/trace_pipe
 VERSION 20070824

Over and over again, it would trigger a massive leak.

## Which versions are affected by CVE-2026-68175?


## How do I fix CVE-2026-68175?

Apply the vendor's patch.

## Is CVE-2026-68175 being exploited?

There is no known exploitation of CVE-2026-68175 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68175 and fix it if it is affected.

What it is: CVE-2026-68175 is a 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-2026-68175 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-2026-68175/ (Markdown: https://insights.sbomify.com/CVE-2026-68175/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68175
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68175
- OSV: https://osv.dev/vulnerability/CVE-2026-68175

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68175/
Summaries are generated and may contain mistakes; the official description above is the record.