Fuller check for invalid NSID in _dl_open.roland/dl-nns

2 files changed, 15 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index 411ef3dcc3..967a8c85ea 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2015-04-17  Roland McGrath  <roland@hack.frob.com>
+
+	* elf/dl-open.c (_dl_open): Use __glibc_unlikely in invalid namespace
+	check.  Reject NSID < 0 and NSID >= dl_nns, and check for DL_NNS==1,
+	before using NSID as an index.
+
 2015-04-17  Il'ya Malakhov <ilmalakhov@yandex.ru>
 
 	[BZ #17825]
diff --git a/elf/dl-open.c b/elf/dl-open.c
index 0dbe07fb68..2d0e082271 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -211,7 +211,7 @@ dl_open_worker (void *a)
       struct link_map *l = _dl_find_dso_for_object ((ElfW(Addr)) caller_dlopen);
 
       if (l)
-        call_map = l;
+	call_map = l;
 
       if (args->nsid == __LM_ID_CALLER)
 	args->nsid = call_map->l_ns;
@@ -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 (__glibc_unlikely (nsid != LM_ID_BASE && nsid != __LM_ID_CALLER)
+	   && (__glibc_unlikely (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()"));