UBUNTU-CVE-2026-98863: High severity ubuntu/linux-hwe-edge vulnerability

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Re-pend GETNESTEDSTATEPAGES if getting said pages fails Re-pend GETNESTEDSTATEPAGES before exiting to userspace if getting the nested pages fails in the KVMRUN path. If userspace re-runs the vCPU, and vmcs02 holds valid PFNs from the previous run of L2, then KVM could re-enter L2 with stale, unpinned PFNs mapped into e.g. the vAPIC page. Note, both SVM and VMX (as of commit 11722439fb20 ("KVM: nVMX: Ensure KVMREQGETNESTEDSTATEPAGES is cleared on VM-Exit") ensure the request is cleared on VM-Exit (including the "forced" case), i.e. there is no risk of double-mapping due to emulated VMLAUNCH/VMRESUME/VMRUN and the request trying to map the nested pages.