[PATCH 3.16.y-ckt 005/129] USB: serial: visor: fix crash on detecting device without write_urbs

[Luis Henriques]

3.16.7-ckt25 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Vladis Dronov <vdronov at redhat.com>

commit cb3232138e37129e88240a98a1d2aba2187ff57c upstream.

The visor driver crashes in clie_5_attach() when a specially crafted USB
device without bulk-out endpoint is detected. This fix adds a check that
the device has proper configuration expected by the driver.

Reported-by: Ralf Spenneberg <ralf at spenneberg.net>
Signed-off-by: Vladis Dronov <vdronov at redhat.com>
Fixes: cfb8da8f69b8 ("USB: visor: fix initialisation of UX50/TH55 devices")
Signed-off-by: Johan Hovold <johan at kernel.org>
Cc: Moritz Muehlenhoff <jmm at inutil.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/serial/visor.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/serial/visor.c b/drivers/usb/serial/visor.c
index 60afb39eb73c..bbc90c059002 100644
--- a/drivers/usb/serial/visor.c
+++ b/drivers/usb/serial/visor.c
@@ -597,8 +597,10 @@ static int clie_5_attach(struct usb_serial *serial)
 	 */
 
 	/* some sanity check */
-	if (serial->num_ports < 2)
-		return -1;
+	if (serial->num_bulk_out < 2) {
+		dev_err(&serial->interface->dev, "missing bulk out endpoints\n");
+		return -ENODEV;
+	}
 
 	/* port 0 now uses the modified endpoint Address */
 	port = serial->port[0];