1 files changed, 26 insertions, 5 deletions

diff --git a/drivers/atm/atmtcp.c b/drivers/atm/atmtcp.c
index 56fa16c85ebf..fa3c76a2b49d 100644
--- a/drivers/atm/atmtcp.c
+++ b/drivers/atm/atmtcp.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* drivers/atm/atmtcp.c - ATM over TCP "device" driver */
 
 /* Written 1997-2000 by Werner Almesberger, EPFL LRC/ICA */
@@ -278,6 +279,19 @@ static struct atm_vcc *find_vcc(struct atm_dev *dev, short vpi, int vci)
         return NULL;
 }
 
+static int atmtcp_c_pre_send(struct atm_vcc *vcc, struct sk_buff *skb)
+{
+	struct atmtcp_hdr *hdr;
+
+	if (skb->len < sizeof(struct atmtcp_hdr))
+		return -EINVAL;
+
+	hdr = (struct atmtcp_hdr *)skb->data;
+	if (hdr->length == ATMTCP_HDR_MAGIC)
+		return -EINVAL;
+
+	return 0;
+}
 
 static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
 {
@@ -287,7 +301,6 @@ static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
 	struct sk_buff *new_skb;
 	int result = 0;
 
-	if (!skb->len) return 0;
 	dev = vcc->dev_data;
 	hdr = (struct atmtcp_hdr *) skb->data;
 	if (hdr->length == ATMTCP_HDR_MAGIC) {
@@ -326,7 +339,7 @@ done:
  */
 
 
-static struct atmdev_ops atmtcp_v_dev_ops = {
+static const struct atmdev_ops atmtcp_v_dev_ops = {
 	.dev_close	= atmtcp_v_dev_close,
 	.open		= atmtcp_v_open,
 	.close		= atmtcp_v_close,
@@ -342,8 +355,9 @@ static struct atmdev_ops atmtcp_v_dev_ops = {
  */
 
 
-static struct atmdev_ops atmtcp_c_dev_ops = {
+static const struct atmdev_ops atmtcp_c_dev_ops = {
 	.close		= atmtcp_c_close,
+	.pre_send	= atmtcp_c_pre_send,
 	.send		= atmtcp_c_send
 };
 
@@ -432,9 +446,15 @@ static int atmtcp_remove_persistent(int itf)
 		return -EMEDIUMTYPE;
 	}
 	dev_data = PRIV(dev);
-	if (!dev_data->persist) return 0;
+	if (!dev_data->persist) {
+		atm_dev_put(dev);
+		return 0;
+	}
 	dev_data->persist = 0;
-	if (PRIV(dev)->vcc) return 0;
+	if (PRIV(dev)->vcc) {
+		atm_dev_put(dev);
+		return 0;
+	}
 	kfree(dev_data);
 	atm_dev_put(dev);
 	atm_dev_deregister(dev);
@@ -487,6 +507,7 @@ static void __exit atmtcp_exit(void)
 	deregister_atm_ioctl(&atmtcp_ioctl_ops);
 }
 
+MODULE_DESCRIPTION("ATM over TCP");
 MODULE_LICENSE("GPL");
 module_init(atmtcp_init);
 module_exit(atmtcp_exit);