# CVE-2025-68376: coresight: ETR: Fix ETR buffer use-after-free issue

> A use-after-free vulnerability in the Linux kernel ETR driver allows local attackers with high privileges to execute arbitrary code or escalate privileges.

- **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:** 24 Dec 2025
- **Updated:** 21 Oct 2026
- **Also known as:** BELL-CVE-2025-68376, DEBIAN-CVE-2025-68376, GHSA-cpp9-j2fg-pjvm, ROOT-OS-DEBIAN-13-CVE-2025-68376, ROOT-OS-UBUNTU-2404-CVE-2025-68376, UBUNTU-CVE-2025-68376

## What is CVE-2025-68376?

CVE-2025-68376 is an use after free vulnerability in Linux, published on 24 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:

coresight: ETR: Fix ETR buffer use-after-free issue

When ETR is enabled as CS_MODE_SYSFS, if the buffer size is changed
and enabled again, currently sysfs_buf will point to the newly
allocated memory(buf_new) and free the old memory(buf_old). But the
etr_buf that is being used by the ETR remains pointed to buf_old, not
updated to buf_new. In this case, it will result in a memory
use-after-free issue.

Fix this by checking ETR's mode before updating and releasing buf_old,
if the mode is CS_MODE_SYSFS, then skip updating and releasing it.

## Which versions are affected by CVE-2025-68376?


## How do I fix CVE-2025-68376?

Apply the vendor's patch.

## Is CVE-2025-68376 being exploited?

There is no known exploitation of CVE-2025-68376 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68376 and fix it if it is affected.

What it is: CVE-2025-68376 is an use after free vulnerability in Linux, published on 24 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-2025-68376 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-2025-68376/ (Markdown: https://insights.sbomify.com/CVE-2025-68376/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68376
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68376
- OSV: https://osv.dev/vulnerability/CVE-2025-68376

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68376/
Summaries are generated and may contain mistakes; the official description above is the record.