From: Johan Hovold <johan@kernel.org>
Date: Tue, 7 Mar 2017 15:11:04 +0000 (+0100)
Subject: USB: iowarrior: fix NULL-deref in write
X-Git-Tag: v4.4.55~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6498086195b9d6939293d35e93b804228158eb7f;p=thirdparty%2Fkernel%2Fstable.git

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>
---

diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index e4d17878743e0..775690bed4c0c 100644
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -804,6 +804,14 @@ 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) &&