[PATCH 3.19.y-ckt 15/56] USB: digi_acceleport: do sanity checking for the number of ports

From: Kamal Mostafa
Date: Tue Apr 12 2016 - 17:06:53 EST


3.19.8-ckt19 -stable review patch. If anyone has any objections, please let me know.

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

From: Oliver Neukum <oneukum@xxxxxxxx>

commit 5a07975ad0a36708c6b0a5b9fea1ff811d0b0c1f upstream.

The driver can be crashed with devices that expose crafted descriptors
with too few endpoints.

See: http://seclists.org/bugtraq/2016/Mar/61

Signed-off-by: Oliver Neukum <ONeukum@xxxxxxxx>
[johan: fix OOB endpoint check and add error messages ]
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/usb/serial/digi_acceleport.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index 12b0e67..3df7b7e 100644
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -1251,8 +1251,27 @@ static int digi_port_init(struct usb_serial_port *port, unsigned port_num)

static int digi_startup(struct usb_serial *serial)
{
+ struct device *dev = &serial->interface->dev;
struct digi_serial *serial_priv;
int ret;
+ int i;
+
+ /* check whether the device has the expected number of endpoints */
+ if (serial->num_port_pointers < serial->type->num_ports + 1) {
+ dev_err(dev, "OOB endpoints missing\n");
+ return -ENODEV;
+ }
+
+ for (i = 0; i < serial->type->num_ports + 1 ; i++) {
+ if (!serial->port[i]->read_urb) {
+ dev_err(dev, "bulk-in endpoint missing\n");
+ return -ENODEV;
+ }
+ if (!serial->port[i]->write_urb) {
+ dev_err(dev, "bulk-out endpoint missing\n");
+ return -ENODEV;
+ }
+ }

serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
if (!serial_priv)
--
2.7.4