[PATCH] USB: don't read past config->interface[] if usb_control_msg() fails in usb_reset_configuration()

[Roel Kluin <roel.kluin@gmail.com>]

After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
break occurred, i equals config->desc.bNumInterfaces. so if
usb_control_msg() failed then after goto reset_old_alts we read from
config->interface[config->desc.bNumInterfaces].

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 9bc95fe..00b49bc 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1466,10 +1466,15 @@ int usb_reset_configuration(struct usb_device *dev)
 			retval = usb_hcd_alloc_bandwidth(dev, NULL,
 					intf->cur_altsetting, alt);
 		if (retval < 0)
-			break;
+			/* If not, reinstate the old alternate settings */
+			goto reset_old_alts;
 	}
-	/* If not, reinstate the old alternate settings */
+	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+			USB_REQ_SET_CONFIGURATION, 0,
+			config->desc.bConfigurationValue, 0,
+			NULL, 0, USB_CTRL_SET_TIMEOUT);
 	if (retval < 0) {
+		i--;
 reset_old_alts:
 		for (; i >= 0; i--) {
 			struct usb_interface *intf = config->interface[i];
@@ -1485,12 +1490,6 @@ reset_old_alts:
 		mutex_unlock(&hcd->bandwidth_mutex);
 		return retval;
 	}
-	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
-			USB_REQ_SET_CONFIGURATION, 0,
-			config->desc.bConfigurationValue, 0,
-			NULL, 0, USB_CTRL_SET_TIMEOUT);
-	if (retval < 0)
-		goto reset_old_alts;
 	mutex_unlock(&hcd->bandwidth_mutex);
 
 	/* re-init hc/hcd interface/endpoint state */