[PATCH 3.10 082/143] usbvision: fix crash on detecting device with invalid configuration

From: Willy Tarreau
Date: Sun Jun 05 2016 - 06:48:49 EST


From: Vladis Dronov <vdronov@xxxxxxxxxx>

commit fa52bd506f274b7619955917abfde355e3d19ffe upstream.

The usbvision driver crashes when a specially crafted usb device with invalid
number of interfaces or endpoints is detected. This fix adds checks that the
device has proper configuration expected by the driver.

Reported-by: Ralf Spenneberg <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Vladis Dronov <vdronov@xxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
---
drivers/media/usb/usbvision/usbvision-video.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c
index 017f4d1..bcfefe6 100644
--- a/drivers/media/usb/usbvision/usbvision-video.c
+++ b/drivers/media/usb/usbvision/usbvision-video.c
@@ -1538,9 +1538,23 @@ static int usbvision_probe(struct usb_interface *intf,

if (usbvision_device_data[model].interface >= 0)
interface = &dev->actconfig->interface[usbvision_device_data[model].interface]->altsetting[0];
- else
+ else if (ifnum < dev->actconfig->desc.bNumInterfaces)
interface = &dev->actconfig->interface[ifnum]->altsetting[0];
+ else {
+ dev_err(&intf->dev, "interface %d is invalid, max is %d\n",
+ ifnum, dev->actconfig->desc.bNumInterfaces - 1);
+ ret = -ENODEV;
+ goto err_usb;
+ }
+
+ if (interface->desc.bNumEndpoints < 2) {
+ dev_err(&intf->dev, "interface %d has %d endpoints, but must"
+ " have minimum 2\n", ifnum, interface->desc.bNumEndpoints);
+ ret = -ENODEV;
+ goto err_usb;
+ }
endpoint = &interface->endpoint[1].desc;
+
if (!usb_endpoint_xfer_isoc(endpoint)) {
dev_err(&intf->dev, "%s: interface %d. has non-ISO endpoint!\n",
__func__, ifnum);
--
2.8.0.rc2.1.gbe9624a