media: v4l2-compat-ioctl32.c: don't copy back the result for certain errors

commit d83a8243aaefe62ace433e4384a4f077bed86acb upstream.

Some ioctls need to copy back the result even if the ioctl returned
an error. However, don't do this for the error code -ENOTTY.
It makes no sense in that cases.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[sw0312.kim: cherry-pick from linux-3.18.y to apply CVE patch]
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Change-Id: I1454b74c7f56e73bef2349528d68d15927fba359

diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index d8a2c755cd8005b1dc3aa000594d25d566b705f2..b4fade8de4501bab264b141fb02f1e579ddec63d 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -947,6 +947,9 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
                set_fs(old_fs);
        }
 
+       if (err == -ENOTTY)
+               return err;
+
        /* Special case: even after an error we need to put the
           results back for these ioctls since the error_idx will
           contain information on which control failed. */