---
id: "CVE-2026-98997"
kind: "vulnerability"
aliases: ["CVE-2026-98997"]
title: "Linux amdgpu driver: doorbell buffer check lets a client wipe shared buffers"
severity: "unknown"
cvss: null
epss: 0.00206
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["amdgpu", "gpu-drivers", "linux", "runtime"]
not_affected_if: []
published_at: "2026-10-23T13:17:21+00:00"
first_seen_at: "2026-10-23T21:57:33+00:00"
updated_at: "2026-10-25T12:38:50+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98997", "first_seen_at": "2026-10-23T21:57:33+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-98997", "first_seen_at": "2026-10-25T12:38:50+00:00"}]
---

# Linux amdgpu driver: doorbell buffer check lets a client wipe shared buffers

The amdgpu GPU driver in the Linux kernel accepted any buffer object as a user queue doorbell, which pins it into the doorbell memory domain and discards its contents. A client on the same device can use this against a buffer another client shared with it, destroying that data.

_Summary, check and fix written by a model from the sources; labelled as such._

## Timeline

- 2026-10-23T21:57:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98997
- 2026-10-25T12:38:50+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-98997

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu/userq: only accept doorbell BOs as queue doorbell

amdgpu_userq_get_doorbell_index() pins any BO passed as doorbell_handle
into the doorbell domain. For a regular BO, TTM moves it with
ttm_bo_move_null() and its contents are lost. Since an importer on the
same device gets the exporter's GEM object, a client can do this to a
buffer another client shared with it.

Reject BOs that were not created in the doorbell domain.

v2: drop the error message, use a local abo variable (Christian)

(cherry picked from commit f7497bbc19db4821c62b9d97b31c9086feb2d917)

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_