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| author | Alan Stern <stern@rowland.harvard.edu> | 2006-03-08 15:14:09 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-03-20 14:50:01 -0800 |
| commit | 6aa35675bbc370e5f11baae7e01a9ab255d8030c (patch) | |
| tree | f42b4adac70483f90bcb3c4de9c4d5db964cf43a | |
| parent | 11a223ae3b86b94391774512e5671600367a305c (diff) | |
| download | linux-6aa35675bbc370e5f11baae7e01a9ab255d8030c.tar.gz linux-6aa35675bbc370e5f11baae7e01a9ab255d8030c.tar.bz2 linux-6aa35675bbc370e5f11baae7e01a9ab255d8030c.zip | |
[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>
| -rw-r--r-- | drivers/usb/core/hub.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 7dd28f8e1cea..8e65f7a237e4 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) { |