Subject: [PATCH 17/37] tipc: fix a memory leak in tipc_nl_node_get_link()

From: Cong Wang <[email-masked]>
Date: Wed, 10 Jan 2018 12:50:25 -0800

[ Upstream commit 59b36613e85fb16ebf9feaf914570879cd5c2a21 ]

When tipc_node_find_by_name() fails, the nlmsg is not
freed.

While on it, switch to a goto label to properly
free it.

Fixes: be9c086715c ("tipc: narrow down exposure of struct tipc_node")
Reported-by: Dmitry Vyukov <[email-masked]>
Cc: Jon Maloy <[email-masked]>
Cc: Ying Xue <[email-masked]>
Signed-off-by: Cong Wang <[email-masked]>
Acked-by: Ying Xue <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/tipc/node.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 198dbc7adbe1..f6c5743c170e 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1848,36 +1848,38 @@ int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
 
 	if (strcmp(name, tipc_bclink_name) == 0) {
 		err = tipc_nl_add_bc_link(net, &msg);
-		if (err) {
-			nlmsg_free(msg.skb);
-			return err;
-		}
+		if (err)
+			goto err_free;
 	} else {
 		int bearer_id;
 		struct tipc_node *node;
 		struct tipc_link *link;
 
 		node = tipc_node_find_by_name(net, name, &bearer_id);
-		if (!node)
-			return -EINVAL;
+		if (!node) {
+			err = -EINVAL;
+			goto err_free;
+		}
 
 		tipc_node_read_lock(node);
 		link = node->links[bearer_id].link;
 		if (!link) {
 			tipc_node_read_unlock(node);
-			nlmsg_free(msg.skb);
-			return -EINVAL;
+			err = -EINVAL;
+			goto err_free;
 		}
 
 		err = __tipc_nl_add_link(net, &msg, link, 0);
 		tipc_node_read_unlock(node);
-		if (err) {
-			nlmsg_free(msg.skb);
-			return err;
-		}
+		if (err)
+			goto err_free;
 	}
 
 	return genlmsg_reply(msg.skb, info);
+
+err_free:
+	nlmsg_free(msg.skb);
+	return err;
 }
 
 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
-- 
2.14.3