can: Fix can_send() handling on dev_queue_xmit() failures

The tx packet counting and the local loopback of CAN frames should only happen in the case that the CAN frame has been enqueued to the netdevice tx queue successfully. Thanks to Andre Naujoks <[email protected]> for reporting this issue. Signed-off-by: Oliver Hartkopp <[email protected]> Signed-off-by: Urs Thuermann <[email protected]> Signed-off-by: David S. Miller <[email protected]>
mrcsosa · May 8, 2008 · c2ab7ac · c2ab7ac
1 parent 33f9936
commit c2ab7ac
Showing 1 changed file with 12 additions and 4 deletions.
diff --git a/net/can/af_can.c b/net/can/af_can.c
@@ -208,6 +208,7 @@ static int can_create(struct net *net, struct socket *sock, int protocol)
  */
 int can_send(struct sk_buff *skb, int loop)
 {
+	struct sk_buff *newskb = NULL;
 	int err;
 
 	if (skb->dev->type != ARPHRD_CAN) {
@@ -244,8 +245,7 @@ int can_send(struct sk_buff *skb, int loop)
 			 * If the interface is not capable to do loopback
 			 * itself, we do it here.
 			 */
-			struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
-
+			newskb = skb_clone(skb, GFP_ATOMIC);
 			if (!newskb) {
 				kfree_skb(skb);
 				return -ENOMEM;
@@ -254,7 +254,6 @@ int can_send(struct sk_buff *skb, int loop)
 			newskb->sk = skb->sk;
 			newskb->ip_summed = CHECKSUM_UNNECESSARY;
 			newskb->pkt_type = PACKET_BROADCAST;
-			netif_rx(newskb);
 		}
 	} else {
 		/* indication for the CAN driver: no loopback required */
@@ -266,11 +265,20 @@ int can_send(struct sk_buff *skb, int loop)
 	if (err > 0)
 		err = net_xmit_errno(err);
 
+	if (err) {
+		if (newskb)
+			kfree_skb(newskb);
+		return err;
+	}
+
+	if (newskb)
+		netif_rx(newskb);
+
 	/* update statistics */
 	can_stats.tx_frames++;
 	can_stats.tx_frames_delta++;
 
-	return err;
+	return 0;
 }
 EXPORT_SYMBOL(can_send);