From: Oliver Neukum <oneu...@suse.com>

An attack using the lack of sanity checking in probe is known. This
patch checks for the existence of a second port.

CVE-2016-3136

Signed-off-by: Oliver Neukum <oneu...@suse.com>
CC: sta...@vger.kernel.org
[johan: add error message ]
Signed-off-by: Johan Hovold <jo...@kernel.org>
---
 drivers/usb/serial/mct_u232.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index 4446b8d70ac2..885655315de1 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -376,14 +376,21 @@ static void mct_u232_msr_to_state(struct usb_serial_port 
*port,
 
 static int mct_u232_port_probe(struct usb_serial_port *port)
 {
+       struct usb_serial *serial = port->serial;
        struct mct_u232_private *priv;
 
+       /* check first to simplify error handling */
+       if (!serial->port[1] || !serial->port[1]->interrupt_in_urb) {
+               dev_err(&port->dev, "expected endpoint missing\n");
+               return -ENODEV;
+       }
+
        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;
 
        /* Use second interrupt-in endpoint for reading. */
-       priv->read_urb = port->serial->port[1]->interrupt_in_urb;
+       priv->read_urb = serial->port[1]->interrupt_in_urb;
        priv->read_urb->context = port;
 
        spin_lock_init(&priv->lock);
-- 
2.7.3

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to