[PATCH]race in ftdio_write

Hi,

this has the same race as the visor driver. The counter must be incremented
under the lock it is checked under.

	Regards
		Oliver

Signed-off-by: Oliver Neukum <[email protected]>
-- 

--- a/drivers/usb/serial/ftdi_sio.c	2007-03-23 14:20:14.000000000 +0100
+++ b/drivers/usb/serial/ftdi_sio.c	2007-03-23 14:20:19.000000000 +0100
@@ -1429,6 +1429,7 @@
 		dbg("%s - write limit hit\n", __FUNCTION__);
 		return 0;
 	}
+	priv->tx_outstanding_urbs++;
 	spin_unlock_irqrestore(&priv->tx_lock, flags);
 
 	data_offset = priv->write_offset;
@@ -1446,14 +1447,15 @@
 	buffer = kmalloc (transfer_size, GFP_ATOMIC);
 	if (!buffer) {
 		err("%s ran out of kernel memory for urb ...", __FUNCTION__);
-		return -ENOMEM;
+		count = -ENOMEM;
+		goto error_no_buffer;
 	}
 
 	urb = usb_alloc_urb(0, GFP_ATOMIC);
 	if (!urb) {
 		err("%s - no more free urbs", __FUNCTION__);
-		kfree (buffer);
-		return -ENOMEM;
+		count = -ENOMEM;
+		goto error_no_urb;
 	}
 
 	/* Copy data */
@@ -1495,10 +1497,9 @@
 	if (status) {
 		err("%s - failed submitting write urb, error %d", __FUNCTION__, status);
 		count = status;
-		kfree (buffer);
+		goto error;
 	} else {
 		spin_lock_irqsave(&priv->tx_lock, flags);
-		++priv->tx_outstanding_urbs;
 		priv->tx_outstanding_bytes += count;
 		priv->tx_bytes += count;
 		spin_unlock_irqrestore(&priv->tx_lock, flags);
@@ -1506,10 +1507,19 @@
 
 	/* we are done with this urb, so let the host driver
 	 * really free it when it is finished with it */
-	usb_free_urb (urb);
+	usb_free_urb(urb);
 
 	dbg("%s write returning: %d", __FUNCTION__, count);
 	return count;
+error:
+	usb_free_urb(urb);
+error_no_urb:
+	kfree (buffer);
+error_no_buffer:
+	spin_lock_irqsave(&priv->tx_lock, flags);
+	priv->tx_outstanding_urbs--;
+	spin_unlock_irqrestore(&priv->tx_lock, flags);
+	return count;
 } /* ftdi_write */
 
 

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