[PATCH 4.9 35/44] USB: iowarrior: fix NULL-deref in write

Greg Kroah-Hartman
2017-03-16T14:34:01Z

From: Johan Hovold <johan@kernel.org>

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>

---
drivers/usb/misc/iowarrior.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -798,6 +798,14 @@ static int iowarrior_probe(struct usb_in
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) &&