USB: iowarrior: fix NULL-deref in write

commit de46e56653de7b3b54baa625bd582635008b8d05 upstream.

Make sure to verify that we have the required interrupt-out endpoint for
IOWarrior56 devices to avoid dereferencing a NULL-pointer in write
should a malicious device lack such an endpoint.

Fixes: 946b960d13c1 ("USB: add driver for iowarrior devices.")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index c19a219..878a346 100644 (file)
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -809,6 +809,14 @@ static int iowarrior_probe(struct usb_interface *interface,
                goto error;
        }
 
+       if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) {
+               if (!dev->int_out_endpoint) {
+                       dev_err(&interface->dev, "no interrupt-out endpoint found\n");
+                       retval = -ENODEV;
+                       goto error;
+               }
+       }
+
        /* we have to check the report_size often, so remember it in the endianess suitable for our machine */
        dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
        if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&