Vblank Counter Vulnerability in AMD GPU Driver

CVE-2026-99090

What is CVE-2026-99090?

A vulnerability in the AMD GPU driver within the Linux kernel allows for improper synchronization during GPU reset operations. Specifically, the issue arises when the vblank counter callback reads display registers without properly acquiring the necessary semaphore. This can lead to access conflicts during GPU recovery, which may subsequently trigger internal kernel assertions and warnings. The proposed fix includes ensuring the reset semaphore is held while reading the vblank counter and scanout position, defaulting to cached values during a reset to mitigate unsafe hardware access. This improvement aims to enhance system stability and avoid warnings related to lock dependency during display operations.

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