From: Vladis Dronov <vdronov@redhat.com>
Date: Mon, 16 Nov 2015 17:55:11 +0000 (-0200)
Subject: [media] usbvision: fix crash on detecting device with invalid configuration
X-Git-Tag: v4.5-rc1~149^2^2~85
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=fa52bd50;p=karo-tx-linux.git

[media] usbvision: fix crash on detecting device with invalid configuration

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@spenneberg.net>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
---

diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c
index 3089d640c82d..de9ff3bb8edd 100644
--- a/drivers/media/usb/usbvision/usbvision-video.c
+++ b/drivers/media/usb/usbvision/usbvision-video.c
@@ -1470,9 +1470,23 @@ 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);