ALSA: compress_core: integer overflow in snd_compr_allocate_buffer()

These are 32 bit values that come from the user, we need to check for
integer overflows or we could end up allocating a smaller buffer than
expected.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/compress_offload.c

@@ -407,6 +407,10 @@ static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
 	unsigned int buffer_size;
 	void *buffer;
 
+	if (params->buffer.fragment_size == 0 ||
+	    params->buffer.fragments > SIZE_MAX / params->buffer.fragment_size)
+		return -EINVAL;
+
 	buffer_size = params->buffer.fragment_size * params->buffer.fragments;
 	if (stream->ops->copy) {
 		buffer = NULL;