[PATCH] USB speedtouch: fix memory leak in error path

Hi Greg, this patch fixes a memory leak in the speedtouch driver.
The leak occurs when the ATM layer submits a skbuff for transmission,
but the driver rejects it (because the device has been unplugged for
example).  The ATM layer requires the driver to free the skbuff in this
case.  The patch is against your 2.6 kernel tree.

drivers/usb/misc/speedtch.c

@@ -299,6 +299,19 @@ static struct usb_driver udsl_usb_driver = {
 };
 
 
+/***********
+**  misc  **
+***********/
+
+static inline void udsl_pop (struct atm_vcc *vcc, struct sk_buff *skb)
+{
+	if (vcc->pop)
+		vcc->pop (vcc, skb);
+	else
+		dev_kfree_skb (skb);
+}
+
+
 /*************
 **  decode  **
 *************/
@@ -720,10 +733,7 @@ static void udsl_process_send (unsigned long data)
 	if (!UDSL_SKB (skb)->num_cells) {
 		struct atm_vcc *vcc = UDSL_SKB (skb)->atm_data.vcc;
 
-		if (vcc->pop)
-			vcc->pop (vcc, skb);
-		else
-			dev_kfree_skb (skb);
+		udsl_pop (vcc, skb);
 		instance->current_skb = NULL;
 
 		atomic_inc (&vcc->stats->tx);
@@ -742,10 +752,7 @@ static void udsl_cancel_send (struct udsl_instance_data *instance, struct atm_vc
 		if (UDSL_SKB (skb)->atm_data.vcc == vcc) {
 			dbg ("udsl_cancel_send: popping skb 0x%p", skb);
 			__skb_unlink (skb, &instance->sndqueue);
-			if (vcc->pop)
-				vcc->pop (vcc, skb);
-			else
-				dev_kfree_skb (skb);
+			udsl_pop (vcc, skb);
 		}
 	spin_unlock_irq (&instance->sndqueue.lock);
 
@@ -753,10 +760,7 @@ static void udsl_cancel_send (struct udsl_instance_data *instance, struct atm_vc
 	if ((skb = instance->current_skb) && (UDSL_SKB (skb)->atm_data.vcc == vcc)) {
 		dbg ("udsl_cancel_send: popping current skb (0x%p)", skb);
 		instance->current_skb = NULL;
-		if (vcc->pop)
-			vcc->pop (vcc, skb);
-		else
-			dev_kfree_skb (skb);
+		udsl_pop (vcc, skb);
 	}
 	tasklet_enable (&instance->send_tasklet);
 	dbg ("udsl_cancel_send done");
@@ -765,22 +769,26 @@ static void udsl_cancel_send (struct udsl_instance_data *instance, struct atm_vc
 static int udsl_atm_send (struct atm_vcc *vcc, struct sk_buff *skb)
 {
 	struct udsl_instance_data *instance = vcc->dev->dev_data;
+	int err;
 
 	vdbg ("udsl_atm_send called (skb 0x%p, len %u)", skb, skb->len);
 
 	if (!instance || !instance->usb_dev) {
 		dbg ("udsl_atm_send: NULL data!");
-		return -ENODEV;
+		err = -ENODEV;
+		goto fail;
 	}
 
 	if (vcc->qos.aal != ATM_AAL5) {
 		dbg ("udsl_atm_send: unsupported ATM type %d!", vcc->qos.aal);
-		return -EINVAL;
+		err = -EINVAL;
+		goto fail;
 	}
 
 	if (skb->len > ATM_MAX_AAL5_PDU) {
 		dbg ("udsl_atm_send: packet too long (%d vs %d)!", skb->len, ATM_MAX_AAL5_PDU);
-		return -EINVAL;
+		err = -EINVAL;
+		goto fail;
 	}
 
 	PACKETDEBUG (skb->data, skb->len);
@@ -790,6 +798,10 @@ static int udsl_atm_send (struct atm_vcc *vcc, struct sk_buff *skb)
 	tasklet_schedule (&instance->send_tasklet);
 
 	return 0;
+
+fail:
+	udsl_pop (vcc, skb);
+	return err;
 }