[PATCH] R128 DRI limits checking.

This got fixed in 2.4, but somehow got missed in 2.6.

drivers/char/drm/r128_state.c

@@ -915,6 +915,9 @@ static int r128_cce_dispatch_write_span( drm_device_t *dev,
 	DRM_DEBUG( "\n" );
 
 	count = depth->n;
+	if (count > 4096 || count <= 0)
+		return -EMSGSIZE;
+
 	if ( DRM_COPY_FROM_USER( &x, depth->x, sizeof(x) ) ) {
 		return DRM_ERR(EFAULT);
 	}
@@ -1008,6 +1011,8 @@ static int r128_cce_dispatch_write_pixels( drm_device_t *dev,
 	DRM_DEBUG( "\n" );
 
 	count = depth->n;
+	if (count > 4096  || count <= 0)
+		return -EMSGSIZE;
 
 	xbuf_size = count * sizeof(*x);
 	ybuf_size = count * sizeof(*y);
@@ -1125,6 +1130,9 @@ static int r128_cce_dispatch_read_span( drm_device_t *dev,
 	DRM_DEBUG( "\n" );
 
 	count = depth->n;
+	if (count > 4096 || count <= 0)
+		return -EMSGSIZE;
+
 	if ( DRM_COPY_FROM_USER( &x, depth->x, sizeof(x) ) ) {
 		return DRM_ERR(EFAULT);
 	}
@@ -1167,6 +1175,9 @@ static int r128_cce_dispatch_read_pixels( drm_device_t *dev,
 	DRM_DEBUG( "%s\n", __FUNCTION__ );
 
 	count = depth->n;
+	if (count > 4096 || count <= 0)
+		return -EMSGSIZE;
+
 	if ( count > dev_priv->depth_pitch ) {
 		count = dev_priv->depth_pitch;
 	}