Commit 6aa35675 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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[PATCH] USB: usbcore: Don't assume a USB configuration includes any interfaces 



In a couple of places, usbcore assumes that a USB device configuration
will have a nonzero number of interfaces.  Having no interfaces may or
may not be allowed by the USB spec; in any event we shouldn't die if we
encounter such a thing.  This patch (as662) removes the assumptions.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 11a223ae

drivers/usb/core/hub.c

+10 −6
Original line number Diff line number Diff line
@@ -1179,8 +1179,11 @@ static int choose_configuration(struct usb_device *udev) 
	c = udev->config;

	num_configs = udev->descriptor.bNumConfigurations;

	for (i = 0; i < num_configs; (i++, c++)) {

		struct usb_interface_descriptor	*desc =

				&c->intf_cache[0]->altsetting->desc;

		struct usb_interface_descriptor	*desc = NULL;



		/* It's possible that a config has no interfaces! */

		if (c->desc.bNumInterfaces > 0)

			desc = &c->intf_cache[0]->altsetting->desc;



		/*

		 * HP's USB bus-powered keyboard has only one configuration
@@ -1215,7 +1218,8 @@ static int choose_configuration(struct usb_device *udev) 
		/* If the first config's first interface is COMM/2/0xff

		 * (MSFT RNDIS), rule it out unless Linux has host-side

		 * RNDIS support. */

		if (i == 0 && desc->bInterfaceClass == USB_CLASS_COMM

		if (i == 0 && desc

				&& desc->bInterfaceClass == USB_CLASS_COMM

				&& desc->bInterfaceSubClass == 2

				&& desc->bInterfaceProtocol == 0xff) {

#ifndef CONFIG_USB_NET_RNDIS
@@ -1231,8 +1235,8 @@ static int choose_configuration(struct usb_device *udev) 
		 * than a vendor-specific driver. */

		else if (udev->descriptor.bDeviceClass !=

						USB_CLASS_VENDOR_SPEC &&

				desc->bInterfaceClass !=

						USB_CLASS_VENDOR_SPEC) {

				(!desc || desc->bInterfaceClass !=

						USB_CLASS_VENDOR_SPEC)) {

			best = c;

			break;

		}
@@ -3024,7 +3028,7 @@ int usb_reset_device(struct usb_device *udev) 
	parent_hub = hdev_to_hub(parent_hdev);



	/* If we're resetting an active hub, take some special actions */

	if (udev->actconfig &&

	if (udev->actconfig && udev->actconfig->desc.bNumInterfaces > 0 &&

			udev->actconfig->interface[0]->dev.driver ==

				&hub_driver.driver &&

			(hub = hdev_to_hub(udev)) != NULL) {

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