From: Sven Eckelmann <sven.eckelmann@openmesh.com>
Date: Thu, 23 Nov 2017 15:04:41 +0100
Subject: batctl: Free nl_sock on genl_ctrl_resolve error

genl_ctrl_resolve may return NULL on errors. The code must then free the
socket which was used to start the genl_ctrl_resolve and stop the function
with an error code.

Fixes: d8dd1ff1a0fe ("batctl: Use netlink to replace some of debugfs")
Signed-off-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

Origin: upstream, https://git.open-mesh.org/batctl.git/commit/cdac2f843c616caaa2a0d3847aeec84c200c62d6

diff --git a/netlink.c b/netlink.c
index 3eb66c9de30c21722bb1e348b055838ea14d18cf..ee58ce8bf16e224374940dddaff61f7b3c5aa4bb 100644
--- a/netlink.c
+++ b/netlink.c
@@ -301,8 +301,10 @@ static char *netlink_get_info(int ifindex, uint8_t nl_cmd, const char *header)
 	genl_connect(sock);
 
 	family = genl_ctrl_resolve(sock, BATADV_NL_NAME);
-	if (family < 0)
+	if (family < 0) {
+		nl_socket_free(sock);
 		return NULL;
+	}
 
 	msg = nlmsg_alloc();
 	if (!msg) {
@@ -410,8 +412,10 @@ int netlink_print_routing_algos(void)
 	genl_connect(sock);
 
 	family = genl_ctrl_resolve(sock, BATADV_NL_NAME);
-	if (family < 0)
-		return -EOPNOTSUPP;
+	if (family < 0) {
+		last_err = -EOPNOTSUPP;
+		goto err_free_sock;
+	}
 
 	msg = nlmsg_alloc();
 	if (!msg) {
@@ -1125,8 +1129,10 @@ static int netlink_print_common(char *mesh_iface, char *orig_iface,
 	genl_connect(sock);
 
 	family = genl_ctrl_resolve(sock, BATADV_NL_NAME);
-	if (family < 0)
-		return -EOPNOTSUPP;
+	if (family < 0) {
+		last_err = -EOPNOTSUPP;
+		goto err_free_sock;
+	}
 
 	ifindex = if_nametoindex(mesh_iface);
 	if (!ifindex) {