From c7153361a4041260719b340f73f2f76b0969235c Mon Sep 17 00:00:00 2001
From: erouault <erouault>
Date: Tue, 20 Dec 2016 17:28:17 +0000
Subject: [PATCH] * tools/tiff2pdf.c: avoid potential heap-based overflow in
 t2p_readwrite_pdf_image_tile(). Fixes
 http://bugzilla.maptools.org/show_bug.cgi?id=2640

---
 ChangeLog        | 6 ++++++
 tools/tiff2pdf.c | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 6be3602..91ba4e6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2016-12-20 Even Rouault <even.rouault at spatialys.com>
+
+	* tools/tiff2pdf.c: avoid potential heap-based overflow in
+	t2p_readwrite_pdf_image_tile().
+	Fixes http://bugzilla.maptools.org/show_bug.cgi?id=2640
+
 2016-12-13 Even Rouault <even.rouault at spatialys.com>
 
 	* libtiff/tif_fax3.h: revert change done on 2016-01-09 that made
diff --git a/tools/tiff2pdf.c b/tools/tiff2pdf.c
index 47d7629..db196e0 100644
--- a/tools/tiff2pdf.c
+++ b/tools/tiff2pdf.c
@@ -2895,7 +2895,7 @@ tsize_t t2p_readwrite_pdf_image_tile(T2P
 				return(0);
 			}
 			if(TIFFGetField(input, TIFFTAG_JPEGTABLES, &count, &jpt) != 0) {
-				if (count >= 4) {
+				if (count > 4) {
                     /* Ignore EOI marker of JpegTables */
 					_TIFFmemcpy(buffer, jpt, count - 2);
 					bufferoffset += count - 2;
