ALSA: virtio: Validate control metadata from the device

In the Linux kernel, the following vulnerability has been resolved: ALSA: virtio: Validate control metadata from the device virtio-snd control handling trusts the device-provided control type and value count returned by the device. That metadata is then used directly to index g_v2a_type_map[] in virtsnd_kctl_info(), and to size loops and memcpy() operations in virtsnd_kctl_get() and virtsnd_kctl_put() against fixed-size virtio_snd_ctl_value and snd_ctl_elem_value arrays. A buggy or malicious device can therefore trigger out-of-bounds access by advertising an invalid control type or an oversized value count. Validate control type and count once in virtsnd_kctl_parse_cfg(), before querying enumerated items or exposing the control to ALSA.