net: caif: fix memory leak in cfusbl_device_notify

commit 7f5d8666 upstream.

In case of caif_enroll_dev() fail, allocated
link_support won't be assigned to the corresponding
structure. So simply free allocated pointer in case
of error.

Fixes: 7ad65bf6 ("caif: Add support for CAIF over CDC NCM USB interface")
Cc: stable@vger.kernel.org
Signed-off-by: NPavel Skripkin <paskripkin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/caif/caif_usb.c

@@ -116,6 +116,11 @@ static struct cflayer *cfusbl_create(int phyid, u8 ethaddr[ETH_ALEN],
 	return (struct cflayer *) this;
 }
 
+static void cfusbl_release(struct cflayer *layer)
+{
+	kfree(layer);
+}
+
 static struct packet_type caif_usb_type __read_mostly = {
 	.type = cpu_to_be16(ETH_P_802_EX1),
 };
@@ -128,6 +133,7 @@ static int cfusbl_device_notify(struct notifier_block *me, unsigned long what,
 	struct cflayer *layer, *link_support;
 	struct usbnet *usbnet;
 	struct usb_device *usbdev;
+	int res;
 
 	/* Check whether we have a NCM device, and find its VID/PID. */
 	if (!(dev->dev.parent && dev->dev.parent->driver &&
@@ -170,8 +176,11 @@ static int cfusbl_device_notify(struct notifier_block *me, unsigned long what,
 	if (dev->num_tx_queues > 1)
 		pr_warn("USB device uses more than one tx queue\n");
 
-	caif_enroll_dev(dev, &common, link_support, CFUSB_MAX_HEADLEN,
+	res = caif_enroll_dev(dev, &common, link_support, CFUSB_MAX_HEADLEN,
 			&layer, &caif_usb_type.func);
+	if (res)
+		goto err;
+
 	if (!pack_added)
 		dev_add_pack(&caif_usb_type);
 	pack_added = true;
@@ -179,6 +188,9 @@ static int cfusbl_device_notify(struct notifier_block *me, unsigned long what,
 	strlcpy(layer->name, dev->name, sizeof(layer->name));
 
 	return 0;
+err:
+	cfusbl_release(link_support);
+	return res;
 }
 
 static struct notifier_block caif_device_notifier = {