USB: core: only clean up what we allocated

commit 32fd87b3 upstream.

When cleaning up the configurations, make sure we only free the number
of configurations and interfaces that we could have allocated.
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/config.c

@@ -768,18 +768,21 @@ void usb_destroy_configuration(struct usb_device *dev)
 		return;
 
 	if (dev->rawdescriptors) {
-		for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
+		for (i = 0; i < dev->descriptor.bNumConfigurations &&
+				i < USB_MAXCONFIG; i++)
 			kfree(dev->rawdescriptors[i]);
 
 		kfree(dev->rawdescriptors);
 		dev->rawdescriptors = NULL;
 	}
 
-	for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
+	for (c = 0; c < dev->descriptor.bNumConfigurations &&
+			c < USB_MAXCONFIG; c++) {
 		struct usb_host_config *cf = &dev->config[c];
 
 		kfree(cf->string);
-		for (i = 0; i < cf->desc.bNumInterfaces; i++) {
+		for (i = 0; i < cf->desc.bNumInterfaces &&
+				i < USB_MAXINTERFACES; i++) {
 			if (cf->intf_cache[i])
 				kref_put(&cf->intf_cache[i]->ref,
 					  usb_release_interface_cache);