diff --git a/drivers/usbdev/cdcacm.h b/drivers/usbdev/cdcacm.h
index aaad0faa62b..23001eebd58 100644
--- a/drivers/usbdev/cdcacm.h
+++ b/drivers/usbdev/cdcacm.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * drivers/usbdev/cdcacm.h
  *
- *   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011-2012, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -119,6 +119,7 @@
  */
 
 #define CDCACM_MXDESCLEN           (64)
+#defien CDCACM_MAXSTRLEN           (CDCACM_MXDESCLEN-2)
 
 /* Device descriptor values */
 
diff --git a/drivers/usbdev/cdcacm_desc.c b/drivers/usbdev/cdcacm_desc.c
index f2c53194e42..a2d2446ad40 100644
--- a/drivers/usbdev/cdcacm_desc.c
+++ b/drivers/usbdev/cdcacm_desc.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * drivers/usbdev/cdcacm_desc.c
  *
- *   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011-2012, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -472,6 +472,11 @@ int cdcacm_mkstrdesc(uint8_t id, struct usb_strdesc_s *strdesc)
     */
 
    len = strlen(str);
+   if (len > (CDCACM_MAXSTRLEN / 2))
+     {
+       len = (CDCACM_MAXSTRLEN / 2);
+     }
+
    for (i = 0, ndata = 0; i < len; i++, ndata += 2)
      {
        strdesc->data[ndata]   = str[i];
diff --git a/drivers/usbdev/pl2303.c b/drivers/usbdev/pl2303.c
index 5adb02b2169..256e85049ad 100644
--- a/drivers/usbdev/pl2303.c
+++ b/drivers/usbdev/pl2303.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * drivers/usbdev/pl2303.c
  *
- *   Copyright (C) 2008-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2013, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * This logic emulates the Prolific PL2303 serial/USB converter
@@ -194,6 +194,7 @@
 /* Buffer big enough for any of our descriptors */
 
 #define PL2303_MXDESCLEN           (64)
+#defien PL2303_MAXSTRLEN           (PL2303_MXDESCLEN-2)
 
 /* Vender specific control requests *******************************************/
 
@@ -871,6 +872,11 @@ static int usbclass_mkstrdesc(uint8_t id, struct usb_strdesc_s *strdesc)
     */
 
    len = strlen(str);
+   if (len > (PL2303_MAXSTRLEN / 2))
+     {
+       len = (PL2303_MAXSTRLEN / 2);
+     }
+
    for (i = 0, ndata = 0; i < len; i++, ndata += 2)
      {
        strdesc->data[ndata]   = str[i];
diff --git a/drivers/usbdev/usbmsc.h b/drivers/usbdev/usbmsc.h
index c98e275bcea..03b3759ded3 100644
--- a/drivers/usbdev/usbmsc.h
+++ b/drivers/usbdev/usbmsc.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * drivers/usbdev/usbmsc.h
  *
- *   Copyright (C) 2008-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2013, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Mass storage class device.  Bulk-only with SCSI subclass.
@@ -269,6 +269,7 @@
 /* Big enough to hold our biggest descriptor */
 
 #define USBMSC_MXDESCLEN              (64)
+#defien USBMSC_MAXSTRLEN              (USBMSC_MXDESCLEN-2)
 
 /* String language */
 
diff --git a/drivers/usbdev/usbmsc_desc.c b/drivers/usbdev/usbmsc_desc.c
index 87fe6d0403f..e958392f4ef 100644
--- a/drivers/usbdev/usbmsc_desc.c
+++ b/drivers/usbdev/usbmsc_desc.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * drivers/usbdev/usbmsc_desc.c
  *
- *   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011-2012, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -287,6 +287,11 @@ int usbmsc_mkstrdesc(uint8_t id, struct usb_strdesc_s *strdesc)
     */
 
    len = strlen(str);
+   if (len > (USBMSC_MAXSTRLEN / 2))
+     {
+       len = (USBMSC_MAXSTRLEN / 2);
+     }
+
    for (i = 0, ndata = 0; i < len; i++, ndata += 2)
      {
        strdesc->data[ndata]   = str[i];