From 5967380c2034dc3d2d518324e513246306ac0347 Mon Sep 17 00:00:00 2001
From: Dirk Ziegelmeier <dirk@ziegelmeier.net>
Date: Fri, 5 May 2017 09:07:40 +0200
Subject: [PATCH] netif_add: avoid passing NULL pointers to subsequent
 functions (reported by Axel Lin)

---
 src/core/netif.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/core/netif.c b/src/core/netif.c
index f9b60077..994bc4fd 100644
--- a/src/core/netif.c
+++ b/src/core/netif.c
@@ -281,6 +281,16 @@ netif_add(struct netif *netif,
 
   LWIP_ASSERT("No init function given", init != NULL);
 
+  if (ipaddr == NULL) {
+    ipaddr = ip_2_ip4(IP4_ADDR_ANY);
+  }
+  if (netmask == NULL) {
+    netmask = ip_2_ip4(IP4_ADDR_ANY);
+  }
+  if (gw == NULL) {
+    gw = ip_2_ip4(IP4_ADDR_ANY);
+  }
+
   /* reset new interface configuration state */
 #if LWIP_IPV4
   ip_addr_set_zero_ip4(&netif->ip_addr);