CVE-2012-1601

La implementación KVM en el núcleo de Linux anterior a la versión V3.3.6 permite a los usuarios del sistema operativo causar una denegación de servicio (puntero NULL a referencia eliminada y caída del sistema operativo del host) al hacer una llamada ioctl KVM_CREATE_IRQCHIP sobre una CPU virtual que ya existe.

KVM is a full virtualization solution for Linux on AMD64 and Intel 64 systems. KVM is a Linux kernel module built for the standard Red Hat Enterprise Linux kernel. A flaw was found in the way the KVM_CREATE_IRQCHIP ioctl was handled. Calling this ioctl when at least one virtual CPU already existed could lead to a NULL pointer dereference later when the VCPU is scheduled to run. A malicious user in the kvm group on the host could use this flaw to crash the host. A flaw was found in the way device memory was handled during guest device removal. Upon successful device removal, memory used by the device was not properly unmapped from the corresponding IOMMU or properly released from the kernel, leading to a memory leak. A malicious user in the kvm group on the host who has the ability to assign a device to a guest could use this flaw to crash the host.