USB: sierra: fix use after free at suspend/resume

commit 8452727de70f6ad850cd6d0aaa18b5d9050aa63b upstream.

Fix use after free or NULL-pointer dereference during suspend and
resume.

The port data may never have been allocated (port probe failed)
or may already have been released by port_remove (e.g. driver is
unloaded) when suspend and resume are called.

Fixes: e6929a9020ac ("USB: support for autosuspend in sierra while
online")

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
index 3ed8459..dd790e3 100644 (file)
--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -999,6 +999,7 @@ static void sierra_release(struct usb_serial *serial)
                portdata = usb_get_serial_port_data(port);
                if (!portdata)
                        continue;
+               usb_set_serial_port_data(port, NULL);
                kfree(portdata);
        }
        kfree(serial->private);
@@ -1015,6 +1016,8 @@ static void stop_read_write_urbs(struct usb_serial *serial)
        for (i = 0; i < serial->num_ports; ++i) {
                port = serial->port[i];
                portdata = usb_get_serial_port_data(port);
+               if (!portdata)
+                       continue;
                sierra_stop_rx_urbs(port);
                usb_kill_anchored_urbs(&portdata->active);
        }
@@ -1057,6 +1060,9 @@ static int sierra_resume(struct usb_serial *serial)
                port = serial->port[i];
                portdata = usb_get_serial_port_data(port);
 
+               if (!portdata)
+                       continue;
+
                while ((urb = usb_get_from_anchor(&portdata->delayed))) {
                        usb_anchor_urb(urb, &portdata->active);
                        intfdata->in_flight++;