releases/3.4.96/usb-usb_wwan-fix-urb-leak-in-write-error-path.patch

   1 From db0904737947d509844e171c9863ecc5b4534005 Mon Sep 17 00:00:00 2001
   2 From: xiao jin <jin.xiao@intel.com>
   3 Date: Mon, 26 May 2014 19:23:13 +0200
   4 Subject: USB: usb_wwan: fix urb leak in write error path
   5
   6 From: xiao jin <jin.xiao@intel.com>
   7
   8 commit db0904737947d509844e171c9863ecc5b4534005 upstream.
   9
  10 When enable usb serial for modem data, sometimes the tty is blocked
  11 in tty_wait_until_sent because portdata->out_busy always is set and
  12 have no chance to be cleared.
  13
  14 We find a bug in write error path. usb_wwan_write set portdata->out_busy
  15 firstly, then try autopm async with error. No out urb submit and no
  16 usb_wwan_outdat_callback to this write, portdata->out_busy can't be
  17 cleared.
  18
  19 This patch clear portdata->out_busy if usb_wwan_write try autopm async
  20 with error.
  21
  22 Fixes: 383cedc3bb43 ("USB: serial: full autosuspend support for the
  23 option driver")
  24
  25 Signed-off-by: xiao jin <jin.xiao@intel.com>
  26 Signed-off-by: Zhang, Qi1 <qi1.zhang@intel.com>
  27 Reviewed-by: David Cohen <david.a.cohen@linux.intel.com>
  28 Signed-off-by: Johan Hovold <jhovold@gmail.com>
  29 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  30
  31 ---
  32  drivers/usb/serial/usb_wwan.c |    4 +++-
  33  1 file changed, 3 insertions(+), 1 deletion(-)
  34
  35 --- a/drivers/usb/serial/usb_wwan.c
  36 +++ b/drivers/usb/serial/usb_wwan.c
  37 @@ -236,8 +236,10 @@ int usb_wwan_write(struct tty_struct *tt
  38                     usb_pipeendpoint(this_urb->pipe), i);
  39
  40                 err = usb_autopm_get_interface_async(port->serial->interface);
  41 -               if (err < 0)
  42 +               if (err < 0) {
  43 +                       clear_bit(i, &portdata->out_busy);
  44                         break;
  45 +               }
  46
  47                 /* send the data */
  48                 memcpy(this_urb->transfer_buffer, buf, todo);