# CVE-2026-93823: drm/amdkfd: Let driver decide buffer size at AMDKFD_IOC_GET_DMABUF_INFO ioctl

> A local attacker with render-group access can trigger a kernel out-of-memory condition via the AMDKFD_IOC_GET_DMABUF_INFO ioctl by specifying a large buffer size.

- **Severity:** Not scored
- **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:** 24 Sep 2026
- **Updated:** 3 Oct 2026
- **Also known as:** AZL-103685, BELL-CVE-2026-93823, DEBIAN-CVE-2026-93823, GHSA-qq85-p63r-6hwh, UBUNTU-CVE-2026-93823

## What is CVE-2026-93823?

CVE-2026-93823 is a denial of service vulnerability in Linux, published on 24 Sep 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:

drm/amdkfd: Let driver decide buffer size at AMDKFD_IOC_GET_DMABUF_INFO ioctl

amdkfd driver needs allocate buffer to return bo metadata to user space. The
buffer size is controlled by user currently. It is a potential security issue
that hostile value (e.g. 2 GiB) lets any render-group user trigger order-MAX
allocation/OOM in kernel context.

This patch first finds bo metadata size. If the size is smaller than user
provided value drive can safely allocate buffer in kernel space and copy to
user space buffer. If not, driver will let user know, not allocate and copy.
User will redo with new buffer in user space.

This patch lets driver decide buffer allocation size to avoid potential hostile
size from user space.

(cherry picked from commit f54ce9e8cbd3abe0eda3a285f54dc4f572fe589a)

## Which versions are affected by CVE-2026-93823?


## How do I fix CVE-2026-93823?

Apply the vendor's patch.

## Is CVE-2026-93823 being exploited?

There is no known exploitation of CVE-2026-93823 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93823 and fix it if it is affected.

What it is: CVE-2026-93823 is a denial of service vulnerability in Linux, published on 24 Sep 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-2026-93823 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-2026-93823/ (Markdown: https://insights.sbomify.com/CVE-2026-93823/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93823
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93823
- OSV: https://osv.dev/vulnerability/CVE-2026-93823

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93823/
Summaries are generated and may contain mistakes; the official description above is the record.