[PATCH 3.16 155/370] USB: serial: cyberjack: fix NULL-deref at open

Ben Hutchings
2017-03-10T13:49:36Z

From: Johan Hovold <johan@kernel.org>

commit 3dca01114dcecb1cf324534cd8d75fd1306a516b upstream.

Fix NULL-pointer dereference when clearing halt at open should the device
lack a bulk-out endpoint.

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
PC is at cyberjack_open+0x40/0x9c [cyberjack]

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/serial/cyberjack.c | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/drivers/usb/serial/cyberjack.c
+++ b/drivers/usb/serial/cyberjack.c
@@ -50,6 +50,7 @@
#define CYBERJACK_PRODUCT_ID 0x0100

/* Function prototypes */
+static int cyberjack_attach(struct usb_serial *serial);
static int cyberjack_port_probe(struct usb_serial_port *port);
static int cyberjack_port_remove(struct usb_serial_port *port);
static int cyberjack_open(struct tty_struct *tty,
@@ -77,6 +78,7 @@ static struct usb_serial_driver cyberjac
.description = "Reiner SCT Cyberjack USB card reader",
.id_table = id_table,
.num_ports = 1,
+ .attach = cyberjack_attach,
.port_probe = cyberjack_port_probe,
.port_remove = cyberjack_port_remove,
.open = cyberjack_open,
@@ -100,6 +102,14 @@ struct cyberjack_private {
short wrsent; /* Data already sent */
};

+static int cyberjack_attach(struct usb_serial *serial)
+{
+ if (serial->num_bulk_out < serial->num_ports)
+ return -ENODEV;
+
+ return 0;
+}
+
static int cyberjack_port_probe(struct usb_serial_port *port)
{
struct cyberjack_private *priv;