USB: idmouse: fix interface sanity checks

Make sure to use the current alternate setting when verifying the
interface descriptors to avoid binding to an invalid interface.

Failing to do so could cause the driver to misbehave or trigger a WARN()
in usb_submit_urb() that kernels with panic_on_warn set would choke on.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191210112601.3561-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/misc/idmouse.c b/drivers/usb/misc/idmouse.c
index 4afb5dd..e9437a1 100644 (file)
--- a/drivers/usb/misc/idmouse.c
+++ b/drivers/usb/misc/idmouse.c
@@ -322,7 +322,7 @@ static int idmouse_probe(struct usb_interface *interface,
        int result;
 
        /* check if we have gotten the data or the hid interface */
-       iface_desc = &interface->altsetting[0];
+       iface_desc = interface->cur_altsetting;
        if (iface_desc->desc.bInterfaceClass != 0x0A)
                return -ENODEV;