CVE-2025-38351 is a vulnerability in the Linux kernel's KVM subsystem related to Hyper-V hypercalls. It involves improper handling of non-canonical guest virtual addresses (GVAs) during paravirtualized TLB flush operations. Non-canonical GVAs passed to Intel's INVVPID instruction cause a VM failure and kernel warnings, while AMD silently ignores them. The fix involves skipping non-canonical GVAs to prevent these failures.