From: Manuel Schölling <manuel.schoelling@gmx.de>
Date: Sat, 7 Jun 2014 21:57:25 +0000 (+0200)
Subject: dns_resolver: assure that dns_query() result is null-terminated
X-Git-Tag: v3.15.7~38
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0e196f4045d09345e2915b0e8f15f89edfe7803;p=thirdparty%2Fkernel%2Fstable.git

dns_resolver: assure that dns_query() result is null-terminated

[ Upstream commit 84a7c0b1db1c17d5ded8d3800228a608e1070b40 ]

dns_query() credulously assumes that keys are null-terminated and
returns a copy of a memory block that is off by one.

Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c
index e7b6d53eef88d..6853d22ebc071 100644
--- a/net/dns_resolver/dns_query.c
+++ b/net/dns_resolver/dns_query.c
@@ -149,7 +149,9 @@ int dns_query(const char *type, const char *name, size_t namelen,
 	if (!*_result)
 		goto put;
 
-	memcpy(*_result, upayload->data, len + 1);
+	memcpy(*_result, upayload->data, len);
+	*_result[len] = '\0';
+
 	if (_expiry)
 		*_expiry = rkey->expiry;