From 5ac417efe66ddd7cd70a98f7f4e32a14ae40a651 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Fri, 5 Jun 2015 08:07:19 -0300 Subject: [PATCH] [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: Mauro Carvalho Chehab --- drivers/media/platform/sh_vou.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/media/platform/sh_vou.c b/drivers/media/platform/sh_vou.c index 829e85c..8b799ba 100644 --- a/drivers/media/platform/sh_vou.c +++ b/drivers/media/platform/sh_vou.c @@ -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, -- 2.7.4