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Commit 5ac417ef authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
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[media] sh_vou: avoid going past arrays 



Smatch reports two issues:
	drivers/media/platform/sh_vou.c:670 vou_adjust_output() error: buffer overflow 'vou_scale_v_num' 3 <= 4
	drivers/media/platform/sh_vou.c:670 vou_adjust_output() error: buffer overflow 'vou_scale_v_den' 3 <= 4

It seems that there's actually a bug here: the same var (idx) is used
as an index for vertical and horizontal scaling arrays. However,
there are 4 elements on the h arrays, and only 3 at the v ones.

On the first loop, it may select index 4 for the horizontal array.

In this case, if the second loop fails to select an index, the
code would keep using 4 for the vertical array, with is past of
the array sizes.

The intent here seems to use index 0, if the scale is not found.

So, use a separate var for the vertical index.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent 7fdc5561

drivers/media/platform/sh_vou.c

+7 −7
Original line number Diff line number Diff line
@@ -600,7 +600,7 @@ static void vou_adjust_output(struct sh_vou_geometry *geo, v4l2_std_id std) 
{

	unsigned int best_err = UINT_MAX, best = geo->in_width,

		width_max, height_max, img_height_max;

	int i, idx = 0;

	int i, idx_h = 0, idx_v = 0;



	if (std & V4L2_STD_525_60) {

		width_max = 858;
@@ -625,7 +625,7 @@ static void vou_adjust_output(struct sh_vou_geometry *geo, v4l2_std_id std) 
		err = abs(found - geo->output.width);

		if (err < best_err) {

			best_err = err;

			idx = i;

			idx_h = i;

			best = found;

		}

		if (!err)
@@ -633,12 +633,12 @@ static void vou_adjust_output(struct sh_vou_geometry *geo, v4l2_std_id std) 
	}



	geo->output.width = best;

	geo->scale_idx_h = idx;

	geo->scale_idx_h = idx_h;

	if (geo->output.left + best > width_max)

		geo->output.left = width_max - best;



	pr_debug("%s(): W %u * %u/%u = %u\n", __func__, geo->in_width,

		 vou_scale_h_num[idx], vou_scale_h_den[idx], best);

		 vou_scale_h_num[idx_h], vou_scale_h_den[idx_h], best);



	best_err = UINT_MAX;
@@ -655,7 +655,7 @@ static void vou_adjust_output(struct sh_vou_geometry *geo, v4l2_std_id std) 
		err = abs(found - geo->output.height);

		if (err < best_err) {

			best_err = err;

			idx = i;

			idx_v = i;

			best = found;

		}

		if (!err)
@@ -663,12 +663,12 @@ static void vou_adjust_output(struct sh_vou_geometry *geo, v4l2_std_id std) 
	}



	geo->output.height = best;

	geo->scale_idx_v = idx;

	geo->scale_idx_v = idx_v;

	if (geo->output.top + best > height_max)

		geo->output.top = height_max - best;



	pr_debug("%s(): H %u * %u/%u = %u\n", __func__, geo->in_height,

		 vou_scale_v_num[idx], vou_scale_v_den[idx], best);

		 vou_scale_v_num[idx_v], vou_scale_v_den[idx_v], best);

}



static int sh_vou_s_fmt_vid_out(struct file *file, void *priv,