CVE-2026-99178 x86/kvm: Don't consume async #PF flags on a kernel #PF in NMI context

The Linux kernel contains a vulnerability in x86/kvm where an async #PF (page not present) event can cause a kernel panic during an NMI context . The issue occurs because if an NMI arrives after an async #PF is injected but before the handler reads the apf_reason.flags, the NMI handler's own page...