[Patch net] tipc: fix a memory leak in tipc_nl_node_get_link()

[Cong Wang]

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 <dvyu...@google.com>
Cc: Jon Maloy <jon.ma...@ericsson.com>
Cc: Ying Xue <ying....@windriver.com>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
---
 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 507017fe0f1b..9036d8756e73 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1880,36 +1880,38 @@ 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)
-- 
2.13.0