[type1] Fix another potential buffer overflow (#45955).

* src/type1/t1parse (T1_Get_Private_Dict): Assure that check for
`eexec' doesn't exceed `limit'.

ChangeLog

@@ -1,3 +1,10 @@
+2015-09-14  Werner Lemberg  <wl@gnu.org>
+
+	[type1] Fix another potential buffer overflow (#45955).
+
+	* src/type1/t1parse (T1_Get_Private_Dict): Assure that check for
+	`eexec' doesn't exceed `limit'.
+
 2015-09-13  Werner Lemberg  <wl@gnu.org>
 
 	Replace `mkinstalldirs' with AC_PROG_MKDIR_P.

src/type1/t1parse.c

@@ -334,7 +334,6 @@
       /* first of all, look at the `eexec' keyword */
       FT_Byte*    cur   = parser->base_dict;
       FT_Byte*    limit = cur + parser->base_len;
-      FT_Byte     c;
       FT_Pointer  pos_lf;
       FT_Bool     test_cr;
 
@@ -342,9 +341,9 @@
     Again:
       for (;;)
       {
-        c = cur[0];
-        if ( c == 'e' && cur + 9 < limit )  /* 9 = 5 letters for `eexec' + */
-                                            /* whitespace + 4 chars        */
+        if ( cur[0] == 'e'   &&
+             cur + 9 < limit )      /* 9 = 5 letters for `eexec' + */
+                                    /* whitespace + 4 chars        */
         {
           if ( cur[1] == 'e' &&
                cur[2] == 'x' &&
@@ -374,8 +373,15 @@
 
       while ( cur < limit )
       {
-        if ( *cur == 'e' && ft_strncmp( (char*)cur, "eexec", 5 ) == 0 )
-          goto Found;
+        if ( cur[0] == 'e'   &&
+             cur + 5 < limit )
+        {
+          if ( cur[1] == 'e' &&
+               cur[2] == 'x' &&
+               cur[3] == 'e' &&
+               cur[4] == 'c' )
+            goto Found;
+        }
 
         T1_Skip_PS_Token( parser );
         if ( parser->root.error )