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authorAlan Stern <stern@rowland.harvard.edu>2006-03-08 15:14:09 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2006-03-20 14:50:01 -0800
commit6aa35675bbc370e5f11baae7e01a9ab255d8030c (patch)
treef42b4adac70483f90bcb3c4de9c4d5db964cf43a /drivers
parent11a223ae3b86b94391774512e5671600367a305c (diff)
[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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/core/hub.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 7dd28f8e1ce..8e65f7a237e 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -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) {