From 2959eda9272a033863c271aff62095abd01bd4e3 Mon Sep 17 00:00:00 2001
From: Arjun Shankar <arjun.is@lostca.se>
Date: Tue, 21 Apr 2015 14:06:31 +0200
Subject: [PATCH] CVE-2015-1781: resolv/nss_dns/dns-host.c buffer overflow
 [BZ#18287]

---
 ChangeLog                 | 6 ++++++
 NEWS                      | 9 ++++++++-
 resolv/nss_dns/dns-host.c | 3 ++-
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c
index b16b0dd..d8c5579 100644
--- a/resolv/nss_dns/dns-host.c
+++ b/resolv/nss_dns/dns-host.c
@@ -615,7 +615,8 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
   int have_to_map = 0;
   uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct host_data);
   buffer += pad;
-  if (__glibc_unlikely (buflen < sizeof (struct host_data) + pad))
+  buflen = buflen > pad ? buflen - pad : 0;
+  if (__glibc_unlikely (buflen < sizeof (struct host_data)))
     {
       /* The buffer is too small.  */
     too_small: