From: Michal Sekletar <sekletar.m@gmail.com>
Date: Thu, 6 Jun 2013 14:13:52 +0000 (+0200)
Subject: dns: Fix segfault with mixed ipv4/ipv6 nameservers
X-Git-Tag: v0.85~2^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F14%2Fhead;p=thirdparty%2Fmtr.git

dns: Fix segfault with mixed ipv4/ipv6 nameservers

Follow-up on bug #1154432.
---

diff --git a/dns.c b/dns.c
index 8ea48ba..371934f 100644
--- a/dns.c
+++ b/dns.c
@@ -1334,6 +1334,9 @@ void dns_ack6(void)
     if ( addrcmp( (void *) &(from6->sin6_addr), (void *) &localhost6,
                   (int) AF_INET6 ) == 0 ) {
       for (i = 0;i < NSCOUNT6;i++) {
+        if (!NSSOCKADDR6(i))
+          continue;
+
 	if ( addrcmp( (void *) &(NSSOCKADDR6(i)->sin6_addr),
 		      (void *) &(from6->sin6_addr), (int) AF_INET6 ) == 0 ||
 	     addrcmp( (void *) &(NSSOCKADDR6(i)->sin6_addr),