USB: iowarrior: fix NULL-deref in write

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.")
Cc: stable <stable@vger.kernel.org>     # 2.6.21
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index 3ad058cbe6ca..37c63cb39714 100644
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -798,6 +798,14 @@ 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 endianness suitable for our machine */
         dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
         if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&