---
id: "CVE-2026-99090"
kind: "vulnerability"
aliases: ["CVE-2026-99090"]
title: "Linux kernel AMD GPU: vblank counter read races GPU reset"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["amdgpu", "desktop", "drm", "linux-kernel", "package"]
not_affected_if: ["no-amd-gpu"]
published_at: "2026-10-26T15:16:47+00:00"
first_seen_at: "2026-10-26T16:02:26+00:00"
updated_at: "2026-10-26T16:04:09+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99090", "first_seen_at": "2026-10-26T16:02:26+00:00"}]
---

# Linux kernel AMD GPU: vblank counter read races GPU reset

The amdgpu driver's vblank counter callback touched display hardware without holding the GPU reset semaphore, so it could run during GPU recovery. The fix serializes those reads against reset and falls back to the cached software count while a reset is in progress.

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

## Timeline

- 2026-10-26T16:02:26+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99090

## From the sources

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

drm/amdgpu: serialize vblank counter reads against GPU reset

The vblank counter callback reads display registers and scanout
position without holding reset_domain->sem. During GPU recovery,
display commit work can call the callback while reset owns the
semaphore for writing. The hardware access then triggers the
lockdep_assert_held() in amdgpu_device_skip_hw_access() and sets
TAINT_WARN when lockdep is enabled.

Try to acquire the reset semaphore for reading before accessing the
hardware, and hold it across the counter and scanout-position reads.
If reset is already in progress, return DRM's cached software vblank
count instead. This avoids blocking behind reset and avoids accessing
display hardware while it is being reset.

The cached count is less accurate than the hardware count, but is
used only when reset prevents a safe hardware read. This addresses
the reset-time warning from this vblank path; it does not suppress or
fix unrelated lockdep warnings.

(cherry picked from commit 51a4359f7431a4be5e42803c8bdaf7e0e5be2934)

---

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