From 82a7fbb1fa7228499ffeb3a57a1d106a9626d57c Mon Sep 17 00:00:00 2001
From: Su Laus <[EMAIL REDACTED]>
Date: Sun, 5 Feb 2023 15:53:15 +0000
Subject: [PATCH] tiffcrop: added check for assumption on composite images
(fixes #496)
tiffcrop: For composite images with more than one region, the combined_length or combined_width always needs to be equal, respectively. Otherwise, even the first section/region copy action might cause buffer overrun. This is now checked before the first copy action.
Closes #496, #497, #498, #500, #501.
---
tools/tiffcrop.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 66 insertions(+), 2 deletions(-)
diff --git a/tools/tiffcrop.c b/tools/tiffcrop.c
index 84e26ac6..480b927c 100644
--- a/tools/tiffcrop.c
+++ b/tools/tiffcrop.c
@@ -5935,18 +5935,40 @@ static int computeInputPixelOffsets(struct crop_mask *crop,
crop->regionlist[i].buffsize = buffsize;
crop->bufftotal += buffsize;
+
+ /* For composite images with more than one region, the
+ * combined_length or combined_width always needs to be equal,
+ * respectively.
+ * Otherwise, even the first section/region copy
+ * action might cause buffer overrun. */
if (crop->img_mode == COMPOSITE_IMAGES)
{
switch (crop->edge_ref)
{
case EDGE_LEFT:
case EDGE_RIGHT:
+ if (i > 0 && zlength != crop->combined_length)
+ {
+ TIFFError(
+ "computeInputPixelOffsets",
+ "Only equal length regions can be combined for "
+ "-E left or right");
+ return (-1);
+ }
crop->combined_length = zlength;
crop->combined_width += zwidth;
break;
case EDGE_BOTTOM:
case EDGE_TOP: /* width from left, length from top */
default:
+ if (i > 0 && zwidth != crop->combined_width)
+ {
+ TIFFError("computeInputPixelOffsets",
+ "Only equal width regions can be "
+ "combined for -E "
+ "top or bottom");
+ return (-1);
+ }
crop->combined_width = zwidth;
crop->combined_length += zlength;
break;
@@ -7301,6 +7323,46 @@ static int extractCompositeRegions(struct image_data *image,
crop->combined_width = 0;
crop->combined_length = 0;
+ /* If there is more than one region, check beforehand whether all the width
+ * and length values of the regions are the same, respectively. */
+ switch (crop->edge_ref)
+ {
+ default:
+ case EDGE_TOP:
+ case EDGE_BOTTOM:
+ for (i = 1; i < crop->selections; i++)
+ {
+ uint32_t crop_width0 =
+ crop->regionlist[i - 1].x2 - crop->regionlist[i - 1].x1 + 1;
+ uint32_t crop_width1 =
+ crop->regionlist[i].x2 - crop->regionlist[i].x1 + 1;
+ if (crop_width0 != crop_width1)
+ {
+ TIFFError("extractCompositeRegions",
+ "Only equal width regions can be combined for -E "
+ "top or bottom");
+ return (1);
+ }
+ }
+ break;
+ case EDGE_LEFT:
+ case EDGE_RIGHT:
+ for (i = 1; i < crop->selections; i++)
+ {
+ uint32_t crop_length0 =
+ crop->regionlist[i - 1].y2 - crop->regionlist[i - 1].y1 + 1;
+ uint32_t crop_length1 =
+ crop->regionlist[i].y2 - crop->regionlist[i].y1 + 1;
+ if (crop_length0 != crop_length1)
+ {
+ TIFFError("extractCompositeRegions",
+ "Only equal length regions can be combined for "
+ "-E left or right");
+ return (1);
+ }
+ }
+ }
+
for (i = 0; i < crop->selections; i++)
{
/* rows, columns, width, length are expressed in pixels */
@@ -7325,7 +7387,8 @@ static int extractCompositeRegions(struct image_data *image,
default:
case EDGE_TOP:
case EDGE_BOTTOM:
- if ((i > 0) && (crop_width != crop->regionlist[i - 1].width))
+ if ((crop->selections > i + 1) &&
+ (crop_width != crop->regionlist[i + 1].width))
{
TIFFError("extractCompositeRegions",
"Only equal width regions can be combined for -E "
@@ -7418,7 +7481,8 @@ static int extractCompositeRegions(struct image_data *image,
case EDGE_LEFT: /* splice the pieces of each row together, side by
side */
case EDGE_RIGHT:
- if ((i > 0) && (crop_length != crop->regionlist[i - 1].length))
+ if ((crop->selections > i + 1) &&
+ (crop_length != crop->regionlist[i + 1].length))
{
TIFFError("extractCompositeRegions",
"Only equal length regions can be combined for "