diff -Nrup a/nss/nsswitch.h b/nss/nsswitch.h
--- a/nss/nsswitch.h	2012-06-30 13:12:34.000000000 -0600
+++ b/nss/nsswitch.h	2012-10-16 12:43:09.377834729 -0600
@@ -198,4 +198,8 @@ extern int __nss_hostname_digits_dots (c
 				       int *h_errnop);
 libc_hidden_proto (__nss_hostname_digits_dots)
 
+/* Maximum number of aliases we allow.  */
+#define MAX_NR_ALIASES  48
+#define MAX_NR_ADDRS    48
+
 #endif	/* nsswitch.h */
diff -Nrup a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c
--- a/resolv/nss_dns/dns-host.c	2012-06-30 13:12:34.000000000 -0600
+++ b/resolv/nss_dns/dns-host.c	2012-10-16 12:43:09.379834766 -0600
@@ -88,10 +88,6 @@
 
 #define RESOLVSORT
 
-/* Maximum number of aliases we allow.  */
-#define MAX_NR_ALIASES	48
-#define MAX_NR_ADDRS	48
-
 #if PACKETSZ > 65536
 # define MAXPACKET	PACKETSZ
 #else
diff -Nrup a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c
--- a/sysdeps/posix/getaddrinfo.c	2012-10-16 12:42:34.398174840 -0600
+++ b/sysdeps/posix/getaddrinfo.c	2012-10-16 12:43:09.381834802 -0600
@@ -568,7 +568,10 @@ gaih_inet (const char *name, const struc
 	     IPv6 scope ids, nor retrieving the canonical name.  */
 	  if (req->ai_family == AF_INET && (req->ai_flags & AI_CANONNAME) == 0)
 	    {
-	      size_t tmpbuflen = 512;
+              /* Add room for struct host_data in resolv/nss_dns/dns-host.c */
+              size_t tmpbuflen = 512 + (MAX_NR_ALIASES+MAX_NR_ADDRS+1)*sizeof(char*)
+                                  + 16 * sizeof(char);
+
 	      assert (tmpbuf == NULL);
 	      tmpbuf = alloca_account (tmpbuflen, alloca_used);
 	      int rc;
@@ -811,7 +814,7 @@ gaih_inet (const char *name, const struc
 	  old_res_options = _res.options;
 	  _res.options &= ~RES_USE_INET6;
 
-	  size_t tmpbuflen = 1024;
+	  size_t tmpbuflen = 1024 + sizeof(struct gaih_addrtuple);
 	  malloc_tmpbuf = !__libc_use_alloca (alloca_used + tmpbuflen);
 	  assert (tmpbuf == NULL);
 	  if (!malloc_tmpbuf)