From: Oliver Neukum <oneukum@suse.com>
Date: Tue, 27 Oct 2015 11:51:34 +0000 (-0200)
Subject: [media] usbvision fix overflow of interfaces array
X-Git-Tag: v4.5-rc1~149^2^2~153
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=588afcc1c0e4;p=karo-tx-linux.git

[media] usbvision fix overflow of interfaces array

This fixes the crash reported in:
http://seclists.org/bugtraq/2015/Oct/35
The interface number needs a sanity check.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Cc: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.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 4aa46caf7e22..3089d640c82d 100644
--- a/drivers/media/usb/usbvision/usbvision-video.c
+++ b/drivers/media/usb/usbvision/usbvision-video.c
@@ -1461,6 +1461,13 @@ static int usbvision_probe(struct usb_interface *intf,
 	printk(KERN_INFO "%s: %s found\n", __func__,
 				usbvision_device_data[model].model_string);
 
+	/*
+	 * this is a security check.
+	 * an exploit using an incorrect bInterfaceNumber is known
+	 */
+	if (ifnum >= USB_MAXINTERFACES || !dev->actconfig->interface[ifnum])
+		return -ENODEV;
+
 	if (usbvision_device_data[model].interface >= 0)
 		interface = &dev->actconfig->interface[usbvision_device_data[model].interface]->altsetting[0];
 	else