From: Sven Eckelmann <sven.eckelmann@openmesh.com>
Date: Thu, 23 Nov 2017 15:04:39 +0100
Subject: batctl: Handle nl_socket_alloc errors

nl_socket_alloc may return NULL on errors. The processing has to be aborted
when this happens.

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/bc6cd37e0d3ce08e3b89e3123ffa87dc55f24c09

diff --git a/netlink.c b/netlink.c
index 64afeedac46bf3eab14a1d89d7db4491fbef8d81..107ca52a4866e25b7b04428d770a885ca4e826d2 100644
--- a/netlink.c
+++ b/netlink.c
@@ -295,6 +295,9 @@ static char *netlink_get_info(int ifindex, uint8_t nl_cmd, const char *header)
 	};
 
 	sock = nl_socket_alloc();
+	if (!sock)
+		return NULL;
+
 	genl_connect(sock);
 
 	family = genl_ctrl_resolve(sock, BATADV_NL_NAME);
@@ -397,6 +400,9 @@ int netlink_print_routing_algos(void)
 	};
 
 	sock = nl_socket_alloc();
+	if (!sock)
+		return -ENOMEM;
+
 	genl_connect(sock);
 
 	family = genl_ctrl_resolve(sock, BATADV_NL_NAME);
@@ -1104,6 +1110,9 @@ static int netlink_print_common(char *mesh_iface, char *orig_iface,
 	int family;
 
 	sock = nl_socket_alloc();
+	if (!sock)
+		return -ENOMEM;
+
 	genl_connect(sock);
 
 	family = genl_ctrl_resolve(sock, BATADV_NL_NAME);