# CVE-2026-68103: drm/amdgpu: reject mapping a reserved doorbell to a new queue

> A race condition in the AMD GPU driver allows overwriting queue mappings, potentially leading to privilege escalation or denial of service.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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-2026-68103, DEBIAN-CVE-2026-68103, GHSA-wgx5-5x9q-wrw8, UBUNTU-CVE-2026-68103

## What is CVE-2026-68103?

CVE-2026-68103 is a high-severity 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:

drm/amdgpu: reject mapping a reserved doorbell to a new queue

When creating an user-queue, the user space
provides a doorbell BO handle and an offset within
the bo to obtain a doorbell.

However current implementation using xa_store_irq()
to store a doorbell, which allows a later queue created
with the same BO and offset parameters to overwrite an
existing queue and doorbell mapping.

This can cause problems like misrouting fence IRQ
processing to a wrong queue, and mislead the cleanup
process of one queue erasing the mapping of another queue.

This commit fixes this issue by replacing xa_store_irq with
xa_insert_irq, which rejects mapping a reserved
doorbell to a newly created queue

(cherry picked from commit 6244eae22966350db52faf9c1369d3b2ffc5de4e)

Weakness: CWE-662 (Improper Synchronization)

## Which versions are affected by CVE-2026-68103?


## How do I fix CVE-2026-68103?

Apply the vendor's patch.

## Is CVE-2026-68103 being exploited?

There is no known exploitation of CVE-2026-68103 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68103 and fix it if it is affected.

What it is: CVE-2026-68103 is a high-severity 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-2026-68103 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-2026-68103/ (Markdown: https://insights.sbomify.com/CVE-2026-68103/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68103
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68103
- OSV: https://osv.dev/vulnerability/CVE-2026-68103

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68103/
Summaries are generated and may contain mistakes; the official description above is the record.