[added to the 4.1 stable tree] USB: serial: visor: fix crash on detecting device without write_urbs

From: Vladis Dronov <redacted>

This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.

===============

[ Upstream commit cb3232138e37129e88240a98a1d2aba2187ff57c ]

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 <redacted>
Signed-off-by: Vladis Dronov <redacted>
Fixes: cfb8da8f69b8 ("USB: visor: fix initialisation of UX50/TH55 devices")
Cc: stable <redacted>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sasha Levin <redacted>
---
 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 c53fbb3..337a0be 100644
--- a/drivers/usb/serial/visor.c
+++ b/drivers/usb/serial/visor.c

@@ -602,8 +602,10 @@ 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];

-- 
2.5.0