Linux Kernel Vulnerability Affects KVM Hypervisor Functionality

CVE-2026-99178

What is CVE-2026-99178?

A race condition exists in the Linux kernel where handling of async page faults (PF) can lead to a kernel panic when an NMI (Non-Maskable Interrupt) occurs during a page fault. Specifically, when an async #PF event is injected, the associated flags remain unhandled while an NMI attempts to process. If the NMI also generates a #PF due to accessing invalid memory, it can corrupt the async #PF flags, causing the kernel to panic under specific circumstances. This issue notably impacts systems using KVM as a hypervisor, leading to stability concerns and potential service disruption.

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