From: Stephen Hemminger <stephen@networkplumber.org>
Date: Wed, 9 Aug 2017 15:39:27 +0000 (-0700)
Subject: vti6: fix local/remote any addr handling
X-Git-Tag: v4.13.0~79
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2a80154fde40b48d0e8afd16ae0eaa046ca05c02;p=thirdparty%2Fiproute2.git

vti6: fix local/remote any addr handling

According to the IPv4 behavior of 'ip' it should be possible
to omit the arguments for local and remote address.
Without this patch omitting these parameters would lead to
uninitialized memory being interpreted as IPv6 addresses.

Reported-by: Christian Langrock <christian.langrock@secunet.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---

diff --git a/ip/link_vti6.c b/ip/link_vti6.c
index be4e33cee..6ea1fc230 100644
--- a/ip/link_vti6.c
+++ b/ip/link_vti6.c
@@ -59,8 +59,8 @@ static int vti6_parse_opt(struct link_util *lu, int argc, char **argv,
 	struct rtattr *tb[IFLA_MAX + 1];
 	struct rtattr *linkinfo[IFLA_INFO_MAX+1];
 	struct rtattr *vtiinfo[IFLA_VTI_MAX + 1];
-	struct in6_addr saddr;
-	struct in6_addr daddr;
+	struct in6_addr saddr = IN6ADDR_ANY_INIT;
+	struct in6_addr daddr = IN6ADDR_ANY_INIT;
 	unsigned int ikey = 0;
 	unsigned int okey = 0;
 	unsigned int link = 0;
@@ -195,8 +195,11 @@ get_failed:
 
 	addattr32(n, 1024, IFLA_VTI_IKEY, ikey);
 	addattr32(n, 1024, IFLA_VTI_OKEY, okey);
-	addattr_l(n, 1024, IFLA_VTI_LOCAL, &saddr, sizeof(saddr));
-	addattr_l(n, 1024, IFLA_VTI_REMOTE, &daddr, sizeof(daddr));
+
+	if (memcmp(&saddr, &in6addr_any, sizeof(in6addr_any)))
+	    addattr_l(n, 1024, IFLA_VTI_LOCAL, &saddr, sizeof(saddr));
+	if (memcmp(&daddr, &in6addr_any, sizeof(in6addr_any)))
+	    addattr_l(n, 1024, IFLA_VTI_REMOTE, &daddr, sizeof(daddr));
 	addattr32(n, 1024, IFLA_VTI_FWMARK, fwmark);
 	if (link)
 		addattr32(n, 1024, IFLA_VTI_LINK, link);