CVE-2020-36311

Se detectó un problema en el kernel de Linux versiones anteriores a 5.9. El archivo arch/x86/kvm/svm/sev.c permite a atacantes causar una denegación de servicio (bloqueo suave) al desencadenar la destrucción de una SEV VM grande (que requiere anular el registro de muchas regiones cifradas), también se conoce como CID-7be74942f184

Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel allowed a guest VM to disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a guest VM could use this to read or write portions of the host's physical memory. Maxim Levitsky discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel did not properly prevent a guest VM from enabling AVIC in nested guest VMs. An attacker in a guest VM could use this to write to portions of the host's physical memory. Various other issues were also addressed.