# CVE-2025-68296: drm, fbcon, vga_switcheroo: Avoid race condition in fbcon setup

> A race condition in Linux kernel VGA switcheroo allows out-of-bounds access, potentially leading to denial of service or code execution.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Dec 2025
- **Updated:** 19 Jun 2026
- **Also known as:** AZL-72667, BELL-CVE-2025-68296, DEBIAN-CVE-2025-68296, GHSA-p2xg-mw87-vf49, ROOT-OS-DEBIAN-11-CVE-2025-68296, ROOT-OS-DEBIAN-12-CVE-2025-68296, ROOT-OS-DEBIAN-13-CVE-2025-68296, ROOT-OS-UBUNTU-2204-CVE-2025-68296, ROOT-OS-UBUNTU-2404-CVE-2025-68296, UBUNTU-CVE-2025-68296

## What is CVE-2025-68296?

CVE-2025-68296 is a vulnerability in Linux, published on 16 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:

drm, fbcon, vga_switcheroo: Avoid race condition in fbcon setup

Protect vga_switcheroo_client_fb_set() with console lock. Avoids OOB
access in fbcon_remap_all(). Without holding the console lock the call
races with switching outputs.

VGA switcheroo calls fbcon_remap_all() when switching clients. The fbcon
function uses struct fb_info.node, which is set by register_framebuffer().
As the fb-helper code currently sets up VGA switcheroo before registering
the framebuffer, the value of node is -1 and therefore not a legal value.
For example, fbcon uses the value within set_con2fb_map() [1] as an index
into an array.

Moving vga_switcheroo_client_fb_set() after register_framebuffer() can
result in VGA switching that does not switch fbcon correctly.

Therefore move vga_switcheroo_client_fb_set() under fbcon_fb_registered(),
which already holds the console lock. Fbdev calls fbcon_fb_registered()
from within register_framebuffer(). Serializes the helper with VGA
switcheroo's call to fbcon_remap_all().

Although vga_switcheroo_client_fb_set() takes an instance of struct fb_info
as parameter, it really only needs the contained fbcon state. Moving the
call to fbcon initialization is therefore cleaner than before. Only amdgpu,
i915, nouveau and radeon support vga_switcheroo. For all other drivers,
this change does nothing.

## Which versions are affected by CVE-2025-68296?


## How do I fix CVE-2025-68296?

Apply the vendor's patch.

## Is CVE-2025-68296 being exploited?

There is no known exploitation of CVE-2025-68296 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68296 and fix it if it is affected.

What it is: CVE-2025-68296 is a vulnerability in Linux, published on 16 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-2025-68296 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-2025-68296/ (Markdown: https://insights.sbomify.com/CVE-2025-68296/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68296
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68296
- OSV: https://osv.dev/vulnerability/CVE-2025-68296

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68296/
Summaries are generated and may contain mistakes; the official description above is the record.