staging: ozwpan: Fix crash for race condition.

Do not allocate a port to new device or process URB when its status is
yet to be read. This avoids race condition when USB core read hub
status a bit late, while new device tries to acquire port.

Signed-off-by: Rupesh Gujare <rupesh.gujare@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/ozwpan/ozhcd.c b/drivers/staging/ozwpan/ozhcd.c
index 2b67107db6b24a8c3d29d4e8922894ae39f57729..4682d782abe750508be061bfbbd1e0f447da0ff2 100644 (file)
--- a/drivers/staging/ozwpan/ozhcd.c
+++ b/drivers/staging/ozwpan/ozhcd.c
@@ -685,7 +685,7 @@ struct oz_port *oz_hcd_pd_arrived(void *hpd)
                struct oz_port *port = &ozhcd->ports[i];
 
                spin_lock(&port->port_lock);
-               if (!(port->flags & OZ_PORT_F_PRESENT)) {
+               if (!(port->flags & (OZ_PORT_F_PRESENT | OZ_PORT_F_CHANGED))) {
                        oz_acquire_port(port, hpd);
                        spin_unlock(&port->port_lock);
                        break;
@@ -1818,7 +1818,8 @@ static int oz_hcd_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
        port =  &ozhcd->ports[port_ix];
        if (port == NULL)
                return -EPIPE;
-       if ((port->flags & OZ_PORT_F_PRESENT) == 0) {
+       if (!(port->flags & OZ_PORT_F_PRESENT) ||
+                               (port->flags & OZ_PORT_F_CHANGED)) {
                oz_dbg(ON, "Refusing URB port_ix = %d devnum = %d\n",
                       port_ix, urb->dev->devnum);
                return -EPIPE;