[PATCH 4.4 062/117] USB: visor: fix null-deref at probe

[Greg Kroah-Hartman]

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

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit cac9b50b0d75a1d50d6c056ff65c005f3224c8e0 upstream.

Fix null-pointer dereference at probe should a (malicious) Treo device
lack the expected endpoints.

Specifically, the Treo port-setup hack was dereferencing the bulk-in and
interrupt-in urbs without first making sure they had been allocated by
core.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/serial/visor.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/usb/serial/visor.c
+++ b/drivers/usb/serial/visor.c
@@ -544,6 +544,11 @@ static int treo_attach(struct usb_serial
 		(serial->num_interrupt_in == 0))
 		return 0;
 
+	if (serial->num_bulk_in < 2 || serial->num_interrupt_in < 2) {
+		dev_err(&serial->interface->dev, "missing endpoints\n");
+		return -ENODEV;
+	}
+
 	/*
 	* It appears that Treos and Kyoceras want to use the
 	* 1st bulk in endpoint to communicate with the 2nd bulk out endpoint,