In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Transfer the hyp stack pages out of the host stage-2… (CVE-2026-98466)

The vulnerability in the Linux kernel's KVM implementation for arm64 involved the function fix_host_ownership() which only walked the linear-map alias of each memblock region. However, the per-CPU hyp stack, mapped in a private virtual address range with a guard page, was not included in this walk. This could lead to incorrect handling of hyp stack pages. The fix modifies the code to walk each stack's virtual address range with the same walker, ensuring proper memory ownership management.

The vulnerability could potentially allow incorrect memory ownership handling of the hyp stack pages in the host stage-2, which may affect the security isolation guarantees of the KVM hypervisor on arm64. No known exploits in the wild have been reported. The exact impact is not detailed in the provided data.

A fix has been implemented to address this vulnerability by modifying the memory ownership walking logic to include the hyp stack's virtual address range. Users should apply the official Linux kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, users should consult the vendor advisory for current remediation guidance.