diff --git a/drivers/virtio/virtio_rng.c b/drivers/virtio/virtio_rng.c
index 9314c0a..b85545c 100644
--- a/drivers/virtio/virtio_rng.c
+++ b/drivers/virtio/virtio_rng.c
@@ -41,6 +41,9 @@
 		while (!virtqueue_get_buf(priv->rng_vq, &rsize))
 			;
 
+		if (rsize > sg.length)
+			return -EIO;
+
 		memcpy(ptr, buf, rsize);
 		len -= rsize;
 		ptr += rsize;