releases/3.18.103/media-v4l2-ioctl.c-don-t-copy-back-the-result-for-enotty.patch

   1 From 181a4a2d5a0a7b43cab08a70710d727e7764ccdd Mon Sep 17 00:00:00 2001
   2 From: Hans Verkuil <hans.verkuil@cisco.com>
   3 Date: Tue, 30 Jan 2018 03:50:01 -0500
   4 Subject: media: v4l2-ioctl.c: don't copy back the result for -ENOTTY
   5
   6 From: Hans Verkuil <hans.verkuil@cisco.com>
   7
   8 commit 181a4a2d5a0a7b43cab08a70710d727e7764ccdd upstream.
   9
  10 If the ioctl returned -ENOTTY, then don't bother copying
  11 back the result as there is no point.
  12
  13 Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
  14 Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
  15 Cc: <stable@vger.kernel.org>      # for v4.15 and up
  16 Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
  17 Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  19
  20 ---
  21  drivers/media/v4l2-core/v4l2-ioctl.c |    5 ++++-
  22  1 file changed, 4 insertions(+), 1 deletion(-)
  23
  24 --- a/drivers/media/v4l2-core/v4l2-ioctl.c
  25 +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
  26 @@ -2539,8 +2539,11 @@ video_usercopy(struct file *file, unsign
  27
  28         /* Handles IOCTL */
  29         err = func(file, cmd, parg);
  30 -       if (err == -ENOIOCTLCMD)
  31 +       if (err == -ENOTTY || err == -ENOIOCTLCMD) {
  32                 err = -ENOTTY;
  33 +               goto out;
  34 +       }
  35 +
  36         if (err == 0) {
  37                 if (cmd == VIDIOC_DQBUF)
  38                         trace_v4l2_dqbuf(video_devdata(file)->minor, parg);