Linux Kernel Vulnerability in ARM64 FPSIMD/SVE/SME State Management

CVE-2025-38170

What is CVE-2025-38170?

A vulnerability exists in the Linux kernel where the logic for handling SME traps can improperly manipulate saved FPSIMD/SVE/SME state during context switching. A race condition during preemption may lead to stale CPU states being reused, causing unexpected warnings in the system. Specifically, the task may show TIF_SME set and TIF_FOREIGN_FPSTATE clear, despite the potential for stale data. To mitigate this issue, the kernel should flush the task state to ensure that the CPU context is properly refreshed, thereby preventing the reuse of outdated information.

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