diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 97450a5..8afe2dd 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -192,10 +192,11 @@
 	if (attach == NULL)
 		return ERR_PTR(-ENOMEM);
 
-	mutex_lock(&dmabuf->lock);
-
 	attach->dev = dev;
 	attach->dmabuf = dmabuf;
+
+	mutex_lock(&dmabuf->lock);
+
 	if (dmabuf->ops->attach) {
 		ret = dmabuf->ops->attach(dmabuf, dev, attach);
 		if (ret)