[PATCH 3.2 032/125] USB: usb_wwan: fix urb leak at shutdown

Ben Hutchings
2014-07-08T19:17:12Z

From: Johan Hovold <jhovold@gmail.com>

commit 79eed03e77d481b55d85d1cfe5a1636a0d3897fd upstream.

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")

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/serial/usb_wwan.c | 34 ++++++++++++++++++++++------------
1 file changed, 22 insertions(+), 12 deletions(-)

--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -434,12 +434,26 @@ int usb_wwan_open(struct tty_struct *tty
}
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;

dbg("%s", __func__);
portdata = usb_get_serial_port_data(port);
@@ -450,6 +464,14 @@ void usb_wwan_close(struct usb_serial_po
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++)
@@ -666,18 +688,6 @@ int usb_wwan_suspend(struct usb_serial *
}
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;