[type1] Fix potential buffer overflow (#45923).

* src/type1/t1parse.c (T1_Get_Private_Dict): Assure `cur' doesn't
point to end of file buffer.

ChangeLog

@@ -1,3 +1,10 @@
+2015-09-13  Werner Lemberg  <wl@gnu.org>
+
+	[type1] Fix potential buffer overflow (#45923).
+
+	* src/type1/t1parse.c (T1_Get_Private_Dict): Assure `cur' doesn't
+	point to end of file buffer.
+
 2015-09-13  Werner Lemberg  <wl@gnu.org>
 
 	[gzip] Fix access of small compressed files (#45937).

src/type1/t1parse.c

@@ -389,6 +389,15 @@
 
       cur   = limit;
       limit = parser->base_dict + parser->base_len;
+
+      if ( cur >= limit )
+      {
+        FT_ERROR(( "T1_Get_Private_Dict:"
+                   " premature end in private dictionary\n" ));
+        error = FT_THROW( Invalid_File_Format );
+        goto Exit;
+      }
+
       goto Again;
 
       /* now determine where to write the _encrypted_ binary private  */