Merge branch 'net-lan78xx-fix-NULL-deref-and-memory-leak'

Johan Hovold says:

====================
net: lan78xx: fix NULL deref and memory leak

The first two patches fix a NULL-pointer dereference at probe that can
be triggered by a malicious device and a small transfer-buffer memory
leak, respectively.

For another subsystem I would have marked them:

	Cc: stable@vger.kernel.org	# 4.3

The third one replaces the driver's current broken endpoint lookup
helper, which could end up accepting incomplete interfaces and whose
results weren't even useeren
Johan
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/lan78xx.c

@@ -377,10 +377,6 @@ struct lan78xx_net {
 	struct tasklet_struct	bh;
 	struct delayed_work	wq;
 
-	struct usb_host_endpoint *ep_blkin;
-	struct usb_host_endpoint *ep_blkout;
-	struct usb_host_endpoint *ep_intr;
-
 	int			msg_enable;
 
 	struct urb		*urb_intr;
@@ -2860,78 +2856,12 @@ lan78xx_start_xmit(struct sk_buff *skb, struct net_device *net)
 	return NETDEV_TX_OK;
 }
 
-static int
-lan78xx_get_endpoints(struct lan78xx_net *dev, struct usb_interface *intf)
-{
-	int tmp;
-	struct usb_host_interface *alt = NULL;
-	struct usb_host_endpoint *in = NULL, *out = NULL;
-	struct usb_host_endpoint *status = NULL;
-
-	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
-		unsigned ep;
-
-		in = NULL;
-		out = NULL;
-		status = NULL;
-		alt = intf->altsetting + tmp;
-
-		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
-			struct usb_host_endpoint *e;
-			int intr = 0;
-
-			e = alt->endpoint + ep;
-			switch (e->desc.bmAttributes) {
-			case USB_ENDPOINT_XFER_INT:
-				if (!usb_endpoint_dir_in(&e->desc))
-					continue;
-				intr = 1;
-				/* FALLTHROUGH */
-			case USB_ENDPOINT_XFER_BULK:
-				break;
-			default:
-				continue;
-			}
-			if (usb_endpoint_dir_in(&e->desc)) {
-				if (!intr && !in)
-					in = e;
-				else if (intr && !status)
-					status = e;
-			} else {
-				if (!out)
-					out = e;
-			}
-		}
-		if (in && out)
-			break;
-	}
-	if (!alt || !in || !out)
-		return -EINVAL;
-
-	dev->pipe_in = usb_rcvbulkpipe(dev->udev,
-				       in->desc.bEndpointAddress &
-				       USB_ENDPOINT_NUMBER_MASK);
-	dev->pipe_out = usb_sndbulkpipe(dev->udev,
-					out->desc.bEndpointAddress &
-					USB_ENDPOINT_NUMBER_MASK);
-	dev->ep_intr = status;
-
-	return 0;
-}
-
 static int lan78xx_bind(struct lan78xx_net *dev, struct usb_interface *intf)
 {
 	struct lan78xx_priv *pdata = NULL;
 	int ret;
 	int i;
 
-	ret = lan78xx_get_endpoints(dev, intf);
-	if (ret) {
-		netdev_warn(dev->net, "lan78xx_get_endpoints failed: %d\n",
-			    ret);
-		return ret;
-	}
-
 	dev->data[0] = (unsigned long)kzalloc(sizeof(*pdata), GFP_KERNEL);
 
 	pdata = (struct lan78xx_priv *)(dev->data[0]);
@@ -3700,6 +3630,7 @@ static void lan78xx_stat_monitor(struct timer_list *t)
 static int lan78xx_probe(struct usb_interface *intf,
 			 const struct usb_device_id *id)
 {
+	struct usb_host_endpoint *ep_blkin, *ep_blkout, *ep_intr;
 	struct lan78xx_net *dev;
 	struct net_device *netdev;
 	struct usb_device *udev;
@@ -3748,6 +3679,34 @@ static int lan78xx_probe(struct usb_interface *intf,
 
 	mutex_init(&dev->stats.access_lock);
 
+	if (intf->cur_altsetting->desc.bNumEndpoints < 3) {
+		ret = -ENODEV;
+		goto out2;
+	}
+
+	dev->pipe_in = usb_rcvbulkpipe(udev, BULK_IN_PIPE);
+	ep_blkin = usb_pipe_endpoint(udev, dev->pipe_in);
+	if (!ep_blkin || !usb_endpoint_is_bulk_in(&ep_blkin->desc)) {
+		ret = -ENODEV;
+		goto out2;
+	}
+
+	dev->pipe_out = usb_sndbulkpipe(udev, BULK_OUT_PIPE);
+	ep_blkout = usb_pipe_endpoint(udev, dev->pipe_out);
+	if (!ep_blkout || !usb_endpoint_is_bulk_out(&ep_blkout->desc)) {
+		ret = -ENODEV;
+		goto out2;
+	}
+
+	ep_intr = &intf->cur_altsetting->endpoint[2];
+	if (!usb_endpoint_is_int_in(&ep_intr->desc)) {
+		ret = -ENODEV;
+		goto out2;
+	}
+
+	dev->pipe_intr = usb_rcvintpipe(dev->udev,
+					usb_endpoint_num(&ep_intr->desc));
+
 	ret = lan78xx_bind(dev, intf);
 	if (ret < 0)
 		goto out2;
@@ -3759,18 +3718,7 @@ static int lan78xx_probe(struct usb_interface *intf,
 	netdev->max_mtu = MAX_SINGLE_PACKET_SIZE;
 	netif_set_gso_max_size(netdev, MAX_SINGLE_PACKET_SIZE - MAX_HEADER);
 
-	dev->ep_blkin = (intf->cur_altsetting)->endpoint + 0;
+	period = ep_intr->desc.bInterval;
-	dev->ep_blkout = (intf->cur_altsetting)->endpoint + 1;
-	dev->ep_intr = (intf->cur_altsetting)->endpoint + 2;
-
-	dev->pipe_in = usb_rcvbulkpipe(udev, BULK_IN_PIPE);
-	dev->pipe_out = usb_sndbulkpipe(udev, BULK_OUT_PIPE);
-
-	dev->pipe_intr = usb_rcvintpipe(dev->udev,
-					dev->ep_intr->desc.bEndpointAddress &
-					USB_ENDPOINT_NUMBER_MASK);
-	period = dev->ep_intr->desc.bInterval;
-
 	maxp = usb_maxpacket(dev->udev, dev->pipe_intr, 0);
 	buf = kmalloc(maxp, GFP_KERNEL);
 	if (buf) {
@@ -3783,6 +3731,7 @@ static int lan78xx_probe(struct usb_interface *intf,
 			usb_fill_int_urb(dev->urb_intr, dev->udev,
 					 dev->pipe_intr, buf, maxp,
 					 intr_complete, dev, period);
+			dev->urb_intr->transfer_flags |= URB_FREE_BUFFER;
 		}
 	}