Re: [PATCH] gspca: add missing .type field check in VIDIOC_G_PARM

[Trent Piepho <xyzzy@speakeasy.org>]

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On Thu, 19 Mar 2009, [ISO-8859-1] Németh Márton wrote:
> David Ellingsworth wrote:
> > 2009/3/18 Németh Márton <nm127@freemail.hu>:
> >> From: Márton Németh <nm127@freemail.hu>
> >>
> >> The gspca webcam driver does not check the .type field of struct v4l2_streamparm.
> >> This field is an input parameter for the driver according to V4L2 API specification,
> >> revision 0.24 [1]. Add the missing check.
> >>
> >> The missing check was recognised by v4l-test 0.10 [2] together with gspca_sunplus driver
> >> and with "Trust 610 LCD POWERC@M ZOOM" webcam. This patch was verified also with
> >> v4l-test 0.10.
> >>
> >> References:
> >> [1] V4L2 API specification, revision 0.24
> >>    http://v4l2spec.bytesex.org/spec/r11680.htm
> >>
> >> [2] v4l-test: Test environment for Video For Linux Two API
> >>    http://v4l-test.sourceforge.net/
> >>
> >> Signed-off-by: Márton Németh <nm127@freemail.hu>
> >> ---
> >> --- linux-2.6.29-rc8/drivers/media/video/gspca/gspca.c.orig     2009-03-14 12:29:38.000000000 +0100
> >> +++ linux-2.6.29-rc8/drivers/media/video/gspca/gspca.c  2009-03-18 16:51:03.000000000 +0100
> >> @@ -1320,6 +1320,9 @@ static int vidioc_g_parm(struct file *fi
> >>  {
> >>        struct gspca_dev *gspca_dev = priv;
> >>
> >> +       if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> >> +               return -EINVAL;
> >> +
> >>        memset(parm, 0, sizeof *parm);
> >>        parm->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> > ^^^^^^^^^^^^^^^^^^^
> > This line should be deleted as it's no longer needed.
>
> Because memset() clears the whole parm structure this line is necessary. In other
> drivers the following code is there:
>
>     tmp = parm->type;
>     memset(parm, 0, sizeof(*parm));
>     parm->type = parm;

The memset isn't needed anymore either, I put it into v4l2_ioctl.  I
removed most of the code like that but I may have missed some drivers.