USB: Fix error cleanup path in airprime

Fix up the error processing path: in usb_submit_urb failed, we forgot
to free buffers. Also, don't free buffers in read callback: less error
prone, 21 LOC less, no need to comment so much. N.B. write path is ok
to do kfree.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 27 deletions

diff --git a/drivers/usb/serial/airprime.c b/drivers/usb/serial/airprime.c
index 0af42e32fa0a..18816bf96a4d 100644
--- a/drivers/usb/serial/airprime.c
+++ b/drivers/usb/serial/airprime.c
@@ -58,11 +58,6 @@ static void airprime_read_bulk_callback(struct urb *urb)
         if (urb->status) {
                 dbg("%s - nonzero read bulk status received: %d",
                     __FUNCTION__, urb->status);
-                /* something happened, so free up the memory for this urb */
-                if (urb->transfer_buffer) {
-                        kfree (urb->transfer_buffer);
-                        urb->transfer_buffer = NULL;
-                }
                 return;
         }
         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
@@ -146,6 +141,8 @@ static int airprime_open(struct usb_serial_port *port, struct file *filp)
                                   airprime_read_bulk_callback, port);
                 result = usb_submit_urb(urb, GFP_KERNEL);
                 if (result) {
+                        usb_free_urb(urb);
+                        kfree(buffer);
                         dev_err(&port->dev,
                                 "%s - failed submitting read urb %d for port %d, error %d\n",
                                 __FUNCTION__, i, port->number, result);
@@ -160,27 +157,12 @@ static int airprime_open(struct usb_serial_port *port, struct file *filp)
         /* some error happened, cancel any submitted urbs and clean up anything that
            got allocated successfully */
 
-        for ( ; i >= 0; --i) {
+        while (i-- != 0) {
                 urb = priv->read_urbp[i];
-                if (urb) {
-                        /* This urb was submitted successfully. So we have to
-                           cancel it.
-                           Unlinking the urb will invoke read_bulk_callback()
-                           with an error status, so its transfer buffer will
-                           be freed there */
-                        if (usb_unlink_urb (urb) != -EINPROGRESS) {
-                                /* comments in drivers/usb/core/urb.c say this
-                                   can only happen if the urb was never submitted,
-                                   or has completed already.
-                                   Either way we may have to free the transfer
-                                   buffer here. */
-                                if (urb->transfer_buffer) {
-                                        kfree (urb->transfer_buffer);
-                                        urb->transfer_buffer = NULL;
-                                }
-                        }
-                        usb_free_urb (urb);
-                }
+                buffer = urb->transfer_buffer;
+                usb_kill_urb (urb);
+                usb_free_urb (urb);
+                kfree (buffer);
         }
 
  out:
@@ -194,10 +176,9 @@ static void airprime_close(struct usb_serial_port *port, struct file * filp)
 
         dbg("%s - port %d", __FUNCTION__, port->number);
 
-        /* killing the urb will invoke read_bulk_callback() with an error status,
-           so the transfer buffer will be freed there */
         for (i = 0; i < NUM_READ_URBS; ++i) {
                 usb_kill_urb (priv->read_urbp[i]);
+                kfree (priv->read_urbp[i]->transfer_buffer);
                 usb_free_urb (priv->read_urbp[i]);
         }