OTP-8451 Harmless buffer overflow by one byte in asn1 and ram_file_drv.

1 files changed, 10 insertions, 6 deletions

diff --git a/lib/asn1/c_src/asn1_erl_driver.c b/lib/asn1/c_src/asn1_erl_driver.c
index cd2e63a363..fd284e5800 100644
--- a/lib/asn1/c_src/asn1_erl_driver.c
+++ b/lib/asn1/c_src/asn1_erl_driver.c
@@ -1,19 +1,19 @@
 /*
  * %CopyrightBegin%
- * 
- * Copyright Ericsson AB 2002-2009. All Rights Reserved.
- * 
+ *
+ * Copyright Ericsson AB 2002-2010. All Rights Reserved.
+ *
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
  * compliance with the License. You should have received a copy of the
  * Erlang Public License along with this software. If not, it can be
  * retrieved online at http://www.erlang.org/.
- * 
+ *
  * Software distributed under the License is distributed on an "AS IS"
  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
  * the License for the specific language governing rights and limitations
  * under the License.
- * 
+ *
  * %CopyrightEnd%
  *
  */
@@ -206,7 +206,11 @@ int asn1_drv_control(ErlDrvData   handle,
   set_port_control_flags(a_data->port, PORT_CONTROL_FLAG_BINARY);
 
   if (command == ASN1_COMPLETE)
-    { /* Do the PER complete encode step */
+    { 
+      if (buf_len==0) {
+	  return 0; /* Avoid binary buffer overwrite (OTP-8451) */
+      }
+      /* Do the PER complete encode step */
       if ((drv_binary = driver_alloc_binary(buf_len))==NULL) {
 	/* error handling */
 	set_port_control_flags(a_data->port, 0);