net/9p: fix memory handling/allocation in rdma_request()

Return -ENOMEM when erroring on kmalloc and fix memory leaks when returning on error.
Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

net/9p/trans_rdma.c

@@ -426,8 +426,10 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
 
 	/* Allocate an fcall for the reply */
 	rpl_context = kmalloc(sizeof *rpl_context, GFP_KERNEL);
-	if (!rpl_context)
+	if (!rpl_context) {
+		err = -ENOMEM;
 		goto err_close;
+	}
 
 	/*
 	 * If the request has a buffer, steal it, otherwise
@@ -445,8 +447,8 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
 	}
 	rpl_context->rc = req->rc;
 	if (!rpl_context->rc) {
-		kfree(rpl_context);
-		goto err_close;
+		err = -ENOMEM;
+		goto err_free2;
 	}
 
 	/*
@@ -458,11 +460,8 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
 	 */
 	if (atomic_inc_return(&rdma->rq_count) <= rdma->rq_depth) {
 		err = post_recv(client, rpl_context);
-		if (err) {
-			kfree(rpl_context->rc);
-			kfree(rpl_context);
-			goto err_close;
-		}
+		if (err)
+			goto err_free1;
 	} else
 		atomic_dec(&rdma->rq_count);
 
@@ -471,8 +470,10 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
 
 	/* Post the request */
 	c = kmalloc(sizeof *c, GFP_KERNEL);
-	if (!c)
-		goto err_close;
+	if (!c) {
+		err = -ENOMEM;
+		goto err_free1;
+	}
 	c->req = req;
 
 	c->busa = ib_dma_map_single(rdma->cm_id->device,
@@ -499,9 +500,15 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
 	return ib_post_send(rdma->qp, &wr, &bad_wr);
 
  error:
+	kfree(c);
+	kfree(rpl_context->rc);
+	kfree(rpl_context);
 	P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
 	return -EIO;
-
+ err_free1:
+	kfree(rpl_context->rc);
+ err_free2:
+	kfree(rpl_context);
  err_close:
 	spin_lock_irqsave(&rdma->req_lock, flags);
 	if (rdma->state < P9_RDMA_CLOSING) {