[PATCH] usb: io_edgeport, cleanup to unicode handling

Clean up the unicode handling in io_edgeport. Make get_string size-limited.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 26 insertions, 16 deletions

diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c
index b606c5968102..c28f1f6902c3 100644
--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -142,7 +142,7 @@ struct edgeport_port {
 
 /* This structure holds all of the individual device information */
 struct edgeport_serial {
-        char                    name[MAX_NAME_LEN+1];           /* string name of this device */
+        char                    name[MAX_NAME_LEN+2];           /* string name of this device */
 
         struct edge_manuf_descriptor    manuf_descriptor;       /* the manufacturer descriptor */
         struct edge_boot_descriptor     boot_descriptor;        /* the boot firmware descriptor */
@@ -270,7 +270,7 @@ static void get_manufacturing_desc	(struct edgeport_serial *edge_serial);
 static void get_boot_desc               (struct edgeport_serial *edge_serial);
 static void load_application_firmware   (struct edgeport_serial *edge_serial);
 
-static void unicode_to_ascii            (char *string, __le16 *unicode, int unicode_size);
+static void unicode_to_ascii(char *string, int buflen, __le16 *unicode, int unicode_size);
 
 
 // ************************************************************************
@@ -373,7 +373,7 @@ static void update_edgeport_E2PROM (struct edgeport_serial *edge_serial)
  *  Get string descriptor from device                                   *
  *                                                                      *
  ************************************************************************/
-static int get_string (struct usb_device *dev, int Id, char *string)
+static int get_string (struct usb_device *dev, int Id, char *string, int buflen)
 {
         struct usb_string_descriptor StringDesc;
         struct usb_string_descriptor *pStringDesc;
@@ -395,7 +395,7 @@ static int get_string (struct usb_device *dev, int Id, char *string)
                 return 0;
         }
 
-        unicode_to_ascii(string,  pStringDesc->wData,     pStringDesc->bLength/2-1);
+        unicode_to_ascii(string, buflen, pStringDesc->wData, pStringDesc->bLength/2);
 
         kfree(pStringDesc);
         return strlen(string);
@@ -2564,16 +2564,20 @@ static void change_port_settings (struct edgeport_port *edge_port, struct termio
  *      ASCII range, but it's only for debugging...
  *      NOTE: expects the unicode in LE format
  ****************************************************************************/
-static void unicode_to_ascii (char *string, __le16 *unicode, int unicode_size)
+static void unicode_to_ascii(char *string, int buflen, __le16 *unicode, int unicode_size)
 {
         int i;
 
-        if (unicode_size <= 0)
+        if (buflen <= 0)        /* never happens, but... */
                 return;
+        --buflen;               /* space for nul */
 
-        for (i = 0; i < unicode_size; ++i)
+        for (i = 0; i < unicode_size; i++) {
+                if (i >= buflen)
+                        break;
                 string[i] = (char)(le16_to_cpu(unicode[i]));
-        string[unicode_size] = 0x00;
+        }
+        string[i] = 0x00;
 }
 
 
@@ -2603,11 +2607,17 @@ static void get_manufacturing_desc (struct edgeport_serial *edge_serial)
                 dbg("  BoardRev:       %d", edge_serial->manuf_descriptor.BoardRev);
                 dbg("  NumPorts:       %d", edge_serial->manuf_descriptor.NumPorts);
                 dbg("  DescDate:       %d/%d/%d", edge_serial->manuf_descriptor.DescDate[0], edge_serial->manuf_descriptor.DescDate[1], edge_serial->manuf_descriptor.DescDate[2]+1900);
-                unicode_to_ascii (string, edge_serial->manuf_descriptor.SerialNumber, edge_serial->manuf_descriptor.SerNumLength/2-1);
+                unicode_to_ascii(string, 30,
+                    edge_serial->manuf_descriptor.SerialNumber,
+                    edge_serial->manuf_descriptor.SerNumLength/2);
                 dbg("  SerialNumber: %s", string);
-                unicode_to_ascii (string, edge_serial->manuf_descriptor.AssemblyNumber, edge_serial->manuf_descriptor.AssemblyNumLength/2-1);
+                unicode_to_ascii(string, 30,
+                    edge_serial->manuf_descriptor.AssemblyNumber,
+                    edge_serial->manuf_descriptor.AssemblyNumLength/2);
                 dbg("  AssemblyNumber: %s", string);
-                unicode_to_ascii (string, edge_serial->manuf_descriptor.OemAssyNumber, edge_serial->manuf_descriptor.OemAssyNumLength/2-1);
+                unicode_to_ascii(string, 30,
+                    edge_serial->manuf_descriptor.OemAssyNumber,
+                    edge_serial->manuf_descriptor.OemAssyNumLength/2);
                 dbg("  OemAssyNumber:  %s", string);
                 dbg("  UartType:       %d", edge_serial->manuf_descriptor.UartType);
                 dbg("  IonPid:         %d", edge_serial->manuf_descriptor.IonPid);
@@ -2735,11 +2745,11 @@ static int edge_startup (struct usb_serial *serial)
         usb_set_serial_data(serial, edge_serial);
 
         /* get the name for the device from the device */
-        if ( (i = get_string(dev, dev->descriptor.iManufacturer, &edge_serial->name[0])) != 0) {
-                edge_serial->name[i-1] = ' ';
-        }
-
-        get_string(dev, dev->descriptor.iProduct, &edge_serial->name[i]);
+        i = get_string(dev, dev->descriptor.iManufacturer,
+            &edge_serial->name[0], MAX_NAME_LEN+1);
+        edge_serial->name[i++] = ' ';
+        get_string(dev, dev->descriptor.iProduct,
+            &edge_serial->name[i], MAX_NAME_LEN+2 - i);
 
         dev_info(&serial->dev->dev, "%s detected\n", edge_serial->name);