From: Sven Eckelmann <sven.eckelmann@openmesh.com>
Date: Thu, 23 Nov 2017 15:04:42 +0100
Subject: batctl: Free nl_sock when if_nametoindex failed

The if_nametoindex can return an error. The code must then free the
previously allocated nl_sock 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/4361841bf76ecd27dcfca6edc30c63b05854d415

diff --git a/netlink.c b/netlink.c
index ee58ce8bf16e224374940dddaff61f7b3c5aa4bb..88a5c95c67989a812231aec7352eecfc4e38c70d 100644
--- a/netlink.c
+++ b/netlink.c
@@ -1137,7 +1137,8 @@ static int netlink_print_common(char *mesh_iface, char *orig_iface,
 	ifindex = if_nametoindex(mesh_iface);
 	if (!ifindex) {
 		fprintf(stderr, "Interface %s is unknown\n", mesh_iface);
-		return -ENODEV;
+		last_err = -ENODEV;
+		goto err_free_sock;
 	}
 
 	if (orig_iface) {
@@ -1145,7 +1146,8 @@ static int netlink_print_common(char *mesh_iface, char *orig_iface,
 		if (!hardifindex) {
 			fprintf(stderr, "Interface %s is unknown\n",
 				orig_iface);
-			return -ENODEV;
+			last_err = -ENODEV;
+			goto err_free_sock;
 		}
 	}