CVE-2026-89928 KVM: x86/mmu: Consume the locked rmap value in the lockless rmap walk

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Consume the locked rmap value in the lockless rmap walk kvmrmaplock deliberately elides the rmap lock when it observes an empty rmap. In that case kvmrmaplockreadonly also re-enables preemption and returns zero, so...