diff --git a/[refs] b/[refs]
index ac9031371b41..83194f0c05ce 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 506ff75c92a44d80da96bc18d9902d29e8236fc6
+refs/heads/master: bf6f036848ab2151c2498f11cb7d31a52a95dd5c
diff --git a/trunk/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/trunk/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 88a179e26de9..7c6f6e3a3c81 100644
--- a/trunk/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/trunk/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -699,10 +699,13 @@ static inline struct vmw_surface *vmw_surface_reference(struct vmw_surface *srf)
 static inline void vmw_dmabuf_unreference(struct vmw_dma_buffer **buf)
 {
 	struct vmw_dma_buffer *tmp_buf = *buf;
-	struct ttm_buffer_object *bo = &tmp_buf->base;
+
 	*buf = NULL;
+	if (tmp_buf != NULL) {
+		struct ttm_buffer_object *bo = &tmp_buf->base;
 
-	ttm_bo_unref(&bo);
+		ttm_bo_unref(&bo);
+	}
 }
 
 static inline struct vmw_dma_buffer *vmw_dmabuf_reference(struct vmw_dma_buffer *buf)