Hi Hans,
Thank you for the patch.
On Tuesday, 30 January 2018 12:26:58 EET Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>
> put_v4l2_window32() didn't copy back the clip list to userspace.
> Drivers can update the clip rectangles, so this should be done.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # for v4.15 and up
> ---
> drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 59
> ++++++++++++++++++--------- 1 file changed, 40 insertions(+), 19
> deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index
> 30c5be1f0549..0df941ca4d90 100644
> --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> @@ -50,6 +50,11 @@ struct v4l2_window32 {
>
> static int get_v4l2_window32(struct v4l2_window *kp, struct v4l2_window32
> __user *up) {
> + struct v4l2_clip32 __user *uclips;
> + struct v4l2_clip __user *kclips;
> + compat_caddr_t p;
> + u32 n;
> +
> if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
> copy_from_user(&kp->w, &up->w, sizeof(up->w)) ||
> get_user(kp->field, &up->field) ||
> @@ -59,38 +64,54 @@ static int get_v4l2_window32(struct v4l2_window *kp,
> struct v4l2_window32 __user return -EFAULT;
> if (kp->clipcount > 2048)
> return -EINVAL;
> - if (kp->clipcount) {
> - struct v4l2_clip32 __user *uclips;
> - struct v4l2_clip __user *kclips;
> - int n = kp->clipcount;
> - compat_caddr_t p;
> + if (!kp->clipcount) {
> + kp->clips = NULL;
> + return 0;
> + }
>
> - if (get_user(p, &up->clips))
> + n = kp->clipcount;
> + if (get_user(p, &up->clips))
> + return -EFAULT;
> + uclips = compat_ptr(p);
> + kclips = compat_alloc_user_space(n * sizeof(*kclips));
> + kp->clips = kclips;
> + while (n--) {
> + if (copy_in_user(&kclips->c, &uclips->c, sizeof(uclips->c)))
> return -EFAULT;
> - uclips = compat_ptr(p);
> - kclips = compat_alloc_user_space(n * sizeof(*kclips));
> - kp->clips = kclips;
> - while (--n >= 0) {
> - if (copy_in_user(&kclips->c, &uclips->c, sizeof(uclips->c)))
> - return -EFAULT;
> - if (put_user(n ? kclips + 1 : NULL, &kclips->next))
> - return -EFAULT;
> - uclips += 1;
> - kclips += 1;
> - }
> - } else
> - kp->clips = NULL;
> + if (put_user(n ? kclips + 1 : NULL, &kclips->next))
> + return -EFAULT;
> + uclips++;
> + kclips++;
> + }
> return 0;
> }
>
> static int put_v4l2_window32(struct v4l2_window *kp, struct v4l2_window32
> __user *up) {
> + struct v4l2_clip __user *kclips = kp->clips;
> + struct v4l2_clip32 __user *uclips;
> + u32 n = kp->clipcount;
> + compat_caddr_t p;
> +
> if (copy_to_user(&up->w, &kp->w, sizeof(kp->w)) ||
> put_user(kp->field, &up->field) ||
> put_user(kp->chromakey, &up->chromakey) ||
> put_user(kp->clipcount, &up->clipcount) ||
> put_user(kp->global_alpha, &up->global_alpha))
> return -EFAULT;
> +
> + if (!kp->clipcount)
> + return 0;
> +
> + if (get_user(p, &up->clips))
> + return -EFAULT;
> + uclips = compat_ptr(p);
This is compat code so I don't care too much, but it would be more readable if
you assigned both kclips and uclips here instead of assigning kclips at the
beginning of the function.
> + while (n--) {
Similarly a for loop would be easier to read.
> + if (copy_in_user(&uclips->c, &kclips->c, sizeof(uclips->c)))
> + return -EFAULT;
> + uclips++;
> + kclips++;
> + }
> return 0;
> }
--
Regards,
Laurent Pinchart