commit 328c44c3670ebf6c1bd790acddce65a12998cd6c
Author: Roland McGrath <roland@hack.frob.com>
Date:   Fri Apr 17 12:11:58 2015 -0700

    Fuller check for invalid NSID in _dl_open.

diff --git a/elf/dl-open.c b/elf/dl-open.c
index 0dbe07f..2d0e082 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -619,8 +619,14 @@ no more namespaces available for dlmopen()"));
   /* Never allow loading a DSO in a namespace which is empty.  Such
      direct placements is only causing problems.  Also don't allow
      loading into a namespace used for auditing.  */
-  else if (__builtin_expect (nsid != LM_ID_BASE && nsid != __LM_ID_CALLER, 0)
-	   && (GL(dl_ns)[nsid]._ns_nloaded == 0
+  else if ((nsid != LM_ID_BASE && nsid != __LM_ID_CALLER)
+	   && ((nsid < 0 || nsid >= GL(dl_nns))
+	       /* This prevents the [NSID] index expressions from being
+		  evaluated, so the compiler won't think that we are
+		  accessing an invalid index here in the !SHARED case where
+		  DL_NNS is 1 and so any NSID != 0 is invalid.  */
+	       || DL_NNS == 1
+	       || GL(dl_ns)[nsid]._ns_nloaded == 0
 	       || GL(dl_ns)[nsid]._ns_loaded->l_auditing))
     _dl_signal_error (EINVAL, file, NULL,
 		      N_("invalid target namespace in dlmopen()"));