CVE-2026-80699

A flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) component for ARM64 architectures. This vulnerability, specifically affecting AmpereOne processors, occurs when a physical interrupt is double-deactivated in a nested virtualization context. An attacker could potentially trigger this condition, leading to the central processing unit (CPU) losing its interrupt pending state and preventing the delivery of future interrupts. This could result in a denial of service (DoS) for the affected system.

A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) ARM64 virtual GIC (vgic) implementation. When running nested virtualization, a physical interrupt that had already been deactivated through the HW bit in the list register could be deactivated a second time. This extra deactivation is normally harmless, but on AmpereOne processors it can hit a CPU erratum under which deactivating a physical interrupt that is not active but is the highest-priority pending interrupt causes the CPU to lose its interrupt pending state and prevents the delivery of future interrupts. Consequently, an attacker with the ability to run a guest workload using KVM/arm64 nested virtualization on affected AmpereOne hardware could trigger a local denial of service, affecting availability only, with no impact on confidentiality or integrity.

Red Hat rates this flaw Moderate (CVSS:3.1: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Red Hat Enterprise Linux 10 and Red Hat In-Vehicle OS 2 (kernel and kernel-ivos-qualcomm components) are affected; the fix is deferred for these products because the upstream fix has not yet been integrated into their kernels, and it will be addressed in a future update, leaving a residual risk of local denial of service on AmpereOne systems using nested virtualization. Other Red Hat Enterprise Linux kernel streams are marked not affected because the vulnerable code is not present in them.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.