USB: idmouse: fix interface sanity checks

commit 59920635b89d74b9207ea803d5e91498d39e8b69 upstream.

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")
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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/usb/misc/idmouse.c b/drivers/usb/misc/idmouse.c
index 6d4e7578571085130ec7a476b73f6173194819fd..066dce850cc65dc6b9cb3bdc4e18bbb59dc5e206 100644 (file)
--- a/drivers/usb/misc/idmouse.c
+++ b/drivers/usb/misc/idmouse.c
@@ -342,7 +342,7 @@ 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;