USB: usb_wwan: fix urb leak at shutdown

The delayed-write queue was never emptied at shutdown (close), something
which could lead to leaked urbs if the port is closed before being
runtime resumed due to a write.

When this happens the output buffer would not drain on close
(closing_wait timeout), and after consecutive opens, writes could be
corrupted with previously buffered data, transfered with reduced
throughput or completely blocked.

Note that unbusy_queued_urb() was simply moved out of CONFIG_PM.

Fixes: 383cedc3bb43 ("USB: serial: full autosuspend support for the
option driver")

Cc: <stable@vger.kernel.org>	# v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 22 insertions, 12 deletions

diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c
index 2b8f02696c00..2ab478b55759 100644
--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -414,12 +414,26 @@ int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
 }
 EXPORT_SYMBOL(usb_wwan_open);
 
+static void unbusy_queued_urb(struct urb *urb,
+                                        struct usb_wwan_port_private *portdata)
+{
+        int i;
+
+        for (i = 0; i < N_OUT_URB; i++) {
+                if (urb == portdata->out_urbs[i]) {
+                        clear_bit(i, &portdata->out_busy);
+                        break;
+                }
+        }
+}
+
 void usb_wwan_close(struct usb_serial_port *port)
 {
         int i;
         struct usb_serial *serial = port->serial;
         struct usb_wwan_port_private *portdata;
         struct usb_wwan_intf_private *intfdata = port->serial->private;
+        struct urb *urb;
 
         portdata = usb_get_serial_port_data(port);
 
@@ -428,6 +442,14 @@ void usb_wwan_close(struct usb_serial_port *port)
         portdata->opened = 0;
         spin_unlock_irq(&intfdata->susp_lock);
 
+        for (;;) {
+                urb = usb_get_from_anchor(&portdata->delayed);
+                if (!urb)
+                        break;
+                unbusy_queued_urb(urb, portdata);
+                usb_autopm_put_interface_async(serial->interface);
+        }
+
         for (i = 0; i < N_IN_URB; i++)
                 usb_kill_urb(portdata->in_urbs[i]);
         for (i = 0; i < N_OUT_URB; i++)
@@ -596,18 +618,6 @@ int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
 }
 EXPORT_SYMBOL(usb_wwan_suspend);
 
-static void unbusy_queued_urb(struct urb *urb, struct usb_wwan_port_private *portdata)
-{
-        int i;
-
-        for (i = 0; i < N_OUT_URB; i++) {
-                if (urb == portdata->out_urbs[i]) {
-                        clear_bit(i, &portdata->out_busy);
-                        break;
-                }
-        }
-}
-
 static void play_delayed(struct usb_serial_port *port)
 {
         struct usb_wwan_intf_private *data;