USB: serial: digi_acceleport: fix OOB data sanity check

[pandora-kernel.git] / drivers / usb / serial / digi_acceleport.c

diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index e59bd95..24c9fc8 100644 (file)
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -1746,6 +1746,7 @@ static int digi_read_oob_callback(struct urb *urb)
        struct usb_serial *serial = port->serial;
        struct tty_struct *tty;
        struct digi_port *priv = usb_get_serial_port_data(port);
+       unsigned char *buf = urb->transfer_buffer;
        int opcode, line, status, val;
        int i;
        unsigned int rts;
@@ -1753,12 +1754,15 @@ static int digi_read_oob_callback(struct urb *urb)
        dbg("digi_read_oob_callback: port=%d, len=%d",
                        priv->dp_port_num, urb->actual_length);
 
+       if (urb->actual_length < 4)
+               return -1;
+
        /* handle each oob command */
-       for (i = 0; i < urb->actual_length - 3;) {
-               opcode = ((unsigned char *)urb->transfer_buffer)[i++];
-               line = ((unsigned char *)urb->transfer_buffer)[i++];
-               status = ((unsigned char *)urb->transfer_buffer)[i++];
-               val = ((unsigned char *)urb->transfer_buffer)[i++];
+       for (i = 0; i < urb->actual_length - 4; i += 4) {
+               opcode = buf[i];
+               line = buf[i + 1];
+               status = buf[i + 2];
+               val = buf[i + 3];
 
                dbg("digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d",
                        opcode, line, status, val);