libtiff: CVE-2023-0800

From ab3024307af0d819be64a25efae2b420952ffd5f Mon Sep 17 00:00:00 2001
From: Markus Koschany <[EMAIL REDACTED]>
Date: Tue, 21 Feb 2023 14:39:52 +0100
Subject: [PATCH] CVE-2023-0800

This is also the fix for CVE-2023-0801, CVE-2023-0802, CVE-2023-0803,
CVE-2023-0804.

Bug-Debian: https://bugs.debian.org/1031632
Origin: https://gitlab.com/libtiff/libtiff/-/commit/33aee1275d9d1384791d2206776eb8152d397f00
---
 tools/tiffcrop.c | 73 +++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 69 insertions(+), 4 deletions(-)

diff --git a/tools/tiffcrop.c b/tools/tiffcrop.c
index 1a5f5229..41efb390 100644
--- a/tools/tiffcrop.c
+++ b/tools/tiffcrop.c
@@ -5304,18 +5304,40 @@ computeInputPixelOffsets(struct crop_mask *crop, struct image_data *image,
 
       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;
@@ -6470,6 +6492,47 @@ extractCompositeRegions(struct image_data *image,  struct crop_mask *crop,
   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 */
@@ -6493,8 +6556,9 @@ extractCompositeRegions(struct image_data *image,  struct crop_mask *crop,
       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 top or bottom");
 	     return (1);
@@ -6574,8 +6638,9 @@ extractCompositeRegions(struct image_data *image,  struct crop_mask *crop,
 	   break;
       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 -E left or right");
 	     return (1);