USB: kl5kusb105: fix DMA buffers on stack

Cc: Oliver Neukum <oliver@neukum.name>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/kl5kusb105.c

@@ -212,10 +212,19 @@ static int klsi_105_get_line_state(struct usb_serial_port *port,
 				   unsigned long *line_state_p)
 {
 	int rc;
-	__u8 status_buf[KLSI_STATUSBUF_LEN] = { -1, -1};
+	u8 *status_buf;
 	__u16 status;
 
 	dev_info(&port->serial->dev->dev, "sending SIO Poll request\n");
+
+	status_buf = kmalloc(KLSI_STATUSBUF_LEN, GFP_KERNEL);
+	if (!status_buf) {
+		dev_err(&port->dev, "%s - out of memory for status buffer.\n",
+				__func__);
+		return -ENOMEM;
+	}
+	status_buf[0] = 0xff;
+	status_buf[1] = 0xff;
 	rc = usb_control_msg(port->serial->dev,
 			     usb_rcvctrlpipe(port->serial->dev, 0),
 			     KL5KUSB105A_SIO_POLL,
@@ -236,6 +245,8 @@ static int klsi_105_get_line_state(struct usb_serial_port *port,
 
 		*line_state_p = klsi_105_status2linestate(status);
 	}
+
+	kfree(status_buf);
 	return rc;
 }
 
@@ -364,7 +375,7 @@ static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
 	int rc;
 	int i;
 	unsigned long line_state;
-	struct klsi_105_port_settings cfg;
+	struct klsi_105_port_settings *cfg;
 	unsigned long flags;
 
 	dbg("%s port %d", __func__, port->number);
@@ -376,12 +387,18 @@ static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
 	 * Then read the modem line control and store values in
 	 * priv->line_state.
 	 */
-	cfg.pktlen   = 5;
-	cfg.baudrate = kl5kusb105a_sio_b9600;
-	cfg.databits = kl5kusb105a_dtb_8;
-	cfg.unknown1 = 0;
-	cfg.unknown2 = 1;
-	klsi_105_chg_port_settings(port, &cfg);
+	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
+	if (!cfg) {
+		dev_err(&port->dev, "%s - out of memory for config buffer.\n",
+				__func__);
+		return -ENOMEM;
+	}
+	cfg->pktlen   = 5;
+	cfg->baudrate = kl5kusb105a_sio_b9600;
+	cfg->databits = kl5kusb105a_dtb_8;
+	cfg->unknown1 = 0;
+	cfg->unknown2 = 1;
+	klsi_105_chg_port_settings(port, cfg);
 
 	/* set up termios structure */
 	spin_lock_irqsave(&priv->lock, flags);
@@ -391,11 +408,11 @@ static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
 	priv->termios.c_lflag = tty->termios->c_lflag;
 	for (i = 0; i < NCCS; i++)
 		priv->termios.c_cc[i] = tty->termios->c_cc[i];
-	priv->cfg.pktlen   = cfg.pktlen;
-	priv->cfg.baudrate = cfg.baudrate;
-	priv->cfg.databits = cfg.databits;
-	priv->cfg.unknown1 = cfg.unknown1;
-	priv->cfg.unknown2 = cfg.unknown2;
+	priv->cfg.pktlen   = cfg->pktlen;
+	priv->cfg.baudrate = cfg->baudrate;
+	priv->cfg.databits = cfg->databits;
+	priv->cfg.unknown1 = cfg->unknown1;
+	priv->cfg.unknown2 = cfg->unknown2;
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	/* READ_ON and urb submission */
@@ -441,6 +458,7 @@ static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
 		retval = rc;
 
 exit:
+	kfree(cfg);
 	return retval;
 } /* klsi_105_open */
 
@@ -714,10 +732,17 @@ static void klsi_105_set_termios(struct tty_struct *tty,
 	unsigned int old_iflag = old_termios->c_iflag;
 	unsigned int cflag = tty->termios->c_cflag;
 	unsigned int old_cflag = old_termios->c_cflag;
-	struct klsi_105_port_settings cfg;
+	struct klsi_105_port_settings *cfg;
 	unsigned long flags;
 	speed_t baud;
 
+	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
+	if (!cfg) {
+		dev_err(&port->dev, "%s - out of memory for config buffer.\n",
+				__func__);
+		return;
+	}
+
 	/* lock while we are modifying the settings */
 	spin_lock_irqsave(&priv->lock, flags);
 
@@ -793,11 +818,11 @@ static void klsi_105_set_termios(struct tty_struct *tty,
 		case CS5:
 			dbg("%s - 5 bits/byte not supported", __func__);
 			spin_unlock_irqrestore(&priv->lock, flags);
-			return ;
+			goto err;
 		case CS6:
 			dbg("%s - 6 bits/byte not supported", __func__);
 			spin_unlock_irqrestore(&priv->lock, flags);
-			return ;
+			goto err;
 		case CS7:
 			priv->cfg.databits = kl5kusb105a_dtb_7;
 			break;
@@ -856,11 +881,13 @@ static void klsi_105_set_termios(struct tty_struct *tty,
 #endif
 		;
 	}
-	memcpy(&cfg, &priv->cfg, sizeof(cfg));
+	memcpy(cfg, &priv->cfg, sizeof(*cfg));
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	/* now commit changes to device */
-	klsi_105_chg_port_settings(port, &cfg);
+	klsi_105_chg_port_settings(port, cfg);
+err:
+	kfree(cfg);
 } /* klsi_105_set_termios */