[cid] Avoid segfault with malformed input (#46250).

* src/cid/cidload.c (cid_read_subrs): Return a proper error code for
unsorted offsets.

ChangeLog

@@ -1,3 +1,10 @@
+2015-10-20  Werner Lemberg  <wl@gnu.org>
+
+	[cid] Avoid segfault with malformed input (#46250).
+
+	* src/cid/cidload.c (cid_read_subrs): Return a proper error code for
+	unsorted offsets.
+
 2015-10-20  StudioEtrange  <nomorgan@gmail.com>
 
 	* CMakeLists.txt: Enable shared library builds on MinGW (#46233).

src/cid/cidload.c

@@ -484,7 +484,11 @@
       /* offsets must be ordered */
       for ( count = 1; count <= num_subrs; count++ )
         if ( offsets[count - 1] > offsets[count] )
+        {
+          FT_TRACE1(( "cid_read_subrs: offsets are not ordered\n" ));
+          error = FT_THROW( Syntax_Error );
           goto Fail;
+        }
 
       /* now, compute the size of subrs charstrings, */
       /* allocate, and read them                     */