[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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2006-03-08 15:14:09 -05:00 committed by Greg Kroah-Hartman
parent 11a223ae3b
commit 6aa35675bb

View File

@ -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) {