Linux Kernel Vulnerability in KVM Affecting Guest-Controlled Indices

CVE-2025-39823

What is CVE-2025-39823?

This vulnerability within the Linux kernel involves the KVM (Kernel-based Virtual Machine) and relates to guest-controlled indices, specifically 'min' and 'dest_id'. It was identified that these indices could lead to speculative execution side-channel attacks. To prevent this, the function array_index_nospec() has been employed with bounds checks to limit the values of these indices, thereby reducing the attack surface and enhancing system security. The sophisticated handling of these indices is essential for maintaining the integrity of virtualized environments against potential exploits.

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