CVE-2026-99090
drm/amdgpu: serialize vblank counter reads against GPU reset
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)
INFO
Published Date :
Oct. 26, 2026, 3:16 p.m.
Last Modified :
Oct. 26, 2026, 3:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Acquire reset semaphore for reading before hardware access.
- Hold semaphore across counter and scanout-position reads.
- Return cached vblank count if reset is in progress.
- Apply the patch to serialize hardware access.
References to Advisories, Solutions, and Tools
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CVE-2026-99090.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-99090 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-99090
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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CVE-2026-99090 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-99090 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Oct. 26, 2026
Action Type Old Value New Value Added 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) Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/99xxx/CVE-2026-99090.json">CVE-2026-99090</a> Added Reference https://git.kernel.org/stable/c/037796d9ca1da97978deaefd88ca5649f6cb69f5 Added Reference https://git.kernel.org/stable/c/11b6193c8841a052b7907006ffb1e02468b1448e Added Reference https://git.kernel.org/stable/c/1a6023edfbb5673f55fab6348f135fb3b1428ea5 Added Reference https://git.kernel.org/stable/c/8d6f773d7479034a574ecc3b585bcd07d46b4824 Added Reference https://git.kernel.org/stable/c/f4a0a1ce147d1a6e428d7cb5e3b99fd695139fc7