usbvision fix overflow of interfaces array

[pandora-kernel.git] / drivers / media / video / usbvision / usbvision-video.c

diff --git a/drivers/media/video/usbvision/usbvision-video.c b/drivers/media/video/usbvision/usbvision-video.c
index 5a74f5e..20787d6 100644 (file)
--- a/drivers/media/video/usbvision/usbvision-video.c
+++ b/drivers/media/video/usbvision/usbvision-video.c
@@ -1425,6 +1425,7 @@ static void usbvision_release(struct usb_usbvision *usbvision)
 
        usbvision_remove_sysfs(usbvision->vdev);
        usbvision_unregister_video(usbvision);
+       kfree(usbvision->alt_max_pkt_size);
 
        usb_free_urb(usbvision->ctrl_urb);
 
@@ -1486,7 +1487,7 @@ static int __devinit usbvision_probe(struct usb_interface *intf,
        const struct usb_host_interface *interface;
        struct usb_usbvision *usbvision = NULL;
        const struct usb_endpoint_descriptor *endpoint;
-       int model, i;
+       int model, i, ret;
 
        PDEBUG(DBG_PROBE, "VID=%#04x, PID=%#04x, ifnum=%u",
                                dev->descriptor.idVendor,
@@ -1495,11 +1496,19 @@ static int __devinit usbvision_probe(struct usb_interface *intf,
        model = devid->driver_info;
        if (model < 0 || model >= usbvision_device_data_size) {
                PDEBUG(DBG_PROBE, "model out of bounds %d", model);
-               return -ENODEV;
+               ret = -ENODEV;
+               goto err_usb;
        }
        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
@@ -1510,18 +1519,21 @@ static int __devinit usbvision_probe(struct usb_interface *intf,
                    __func__, ifnum);
                dev_err(&intf->dev, "%s: Endpoint attributes %d",
                    __func__, endpoint->bmAttributes);
-               return -ENODEV;
+               ret = -ENODEV;
+               goto err_usb;
        }
        if (usb_endpoint_dir_out(endpoint)) {
                dev_err(&intf->dev, "%s: interface %d. has ISO OUT endpoint!\n",
                    __func__, ifnum);
-               return -ENODEV;
+               ret = -ENODEV;
+               goto err_usb;
        }
 
        usbvision = usbvision_alloc(dev, intf);
        if (usbvision == NULL) {
                dev_err(&intf->dev, "%s: couldn't allocate USBVision struct\n", __func__);
-               return -ENOMEM;
+               ret = -ENOMEM;
+               goto err_usb;
        }
 
        if (dev->descriptor.bNumConfigurations > 1)
@@ -1540,7 +1552,8 @@ static int __devinit usbvision_probe(struct usb_interface *intf,
        usbvision->alt_max_pkt_size = kmalloc(32 * usbvision->num_alt, GFP_KERNEL);
        if (usbvision->alt_max_pkt_size == NULL) {
                dev_err(&intf->dev, "usbvision: out of memory!\n");
-               return -ENOMEM;
+               ret = -ENOMEM;
+               goto err_pkt;
        }
 
        for (i = 0; i < usbvision->num_alt; i++) {
@@ -1575,6 +1588,12 @@ static int __devinit usbvision_probe(struct usb_interface *intf,
 
        PDEBUG(DBG_PROBE, "success");
        return 0;
+
+err_pkt:
+       usbvision_release(usbvision);
+err_usb:
+       usb_put_dev(dev);
+       return ret;
 }