Original patch from: gentoo/src/patchsets/glibc/2.9/0050_all_glibc-_nss_dns_gethostbyaddr2_r-check-and-adjust-the-buffer-alignment.patch

 -= BEGIN original header =-

 http://sourceware.org/ml/libc-alpha/2009-01/msg00000.html

 From 8ad7030880eaa18dcabf8e284e79026301fd3fa4 Mon Sep 17 00:00:00 2001

 From: Ulrich Drepper <drepper@redhat.com>

 Date: Thu, 8 Jan 2009 00:02:38 +0000

 Subject: [PATCH] (_nss_dns_gethostbyaddr2_r): Check and adjust the buffer alignment.

 -= END original header =-

 diff -durN glibc-2_9.orig/resolv/nss_dns/dns-host.c glibc-2_9/resolv/nss_dns/dns-host.c

 --- glibc-2_9.orig/resolv/nss_dns/dns-host.c	2008-11-12 08:52:20.000000000 +0100

 +++ glibc-2_9/resolv/nss_dns/dns-host.c	2009-02-02 22:00:36.000000000 +0100

 @@ -364,6 +364,19 @@

    int n, status;

    int olderr = errno;

 + uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct host_data);

 + buffer += pad;

 + buflen = buflen > pad ? buflen - pad : 0;

 +

 + if (__builtin_expect (buflen < sizeof (struct host_data), 0))

 +   {

 +     *errnop = ERANGE;

 +     *h_errnop = NETDB_INTERNAL;

 +     return NSS_STATUS_TRYAGAIN;

 +   }

 +

 + host_data = (struct host_data *) buffer;

 +

    if (__res_maybe_init (&_res, 0) == -1)

      return NSS_STATUS_UNAVAIL;