USB: fix race in ftdio_write

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

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Oliver Neukum 2007-03-23 14:30:16 +01:00 committed by Greg Kroah-Hartman
parent b80349b17c
commit 62127a585c

View File

@ -1433,6 +1433,7 @@ static int ftdi_write (struct usb_serial_port *port,
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;
@ -1450,14 +1451,15 @@ static int ftdi_write (struct usb_serial_port *port,
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 */
@ -1499,10 +1501,9 @@ static int ftdi_write (struct usb_serial_port *port,
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);
@ -1510,10 +1511,19 @@ static int ftdi_write (struct usb_serial_port *port,
/* 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 */