From 78dab0996f74644381c9d5c4461208abd9923351 Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Fri, 2 Dec 2016 22:13:32 +0000
Subject: [PATCH] * tools/tiffcp.c: avoid uint32 underflow in cpDecodedStrips
 that can cause various issues, such as buffer overflows in the library.
 Reported by Agostino Sarubbo. Fixes
 http://bugzilla.maptools.org/show_bug.cgi?id=2598

---
 ChangeLog      | 7 +++++++
 tools/tiffcp.c | 4 ++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 668b66ad..0f154d66 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2016-12-02 Even Rouault <even.rouault at spatialys.com>
+
+	* tools/tiffcp.c: avoid uint32 underflow in cpDecodedStrips that 
+	can cause various issues, such as buffer overflows in the library.
+	Reported by Agostino Sarubbo.
+	Fixes http://bugzilla.maptools.org/show_bug.cgi?id=2598
+
 2016-12-02 Even Rouault <even.rouault at spatialys.com>
 
 	* libtiff/tif_read.c, libtiff/tiffiop.h: fix uint32 overflow in
diff --git a/tools/tiffcp.c b/tools/tiffcp.c
index 338a3d11..6dfb9a91 100644
--- a/tools/tiffcp.c
+++ b/tools/tiffcp.c
@@ -1,4 +1,4 @@
-/* $Id: tiffcp.c,v 1.55 2016-10-08 15:54:57 erouault Exp $ */
+/* $Id: tiffcp.c,v 1.56 2016-12-02 22:13:32 erouault Exp $ */
 
 /*
  * Copyright (c) 1988-1997 Sam Leffler
@@ -985,7 +985,7 @@ DECLAREcpFunc(cpDecodedStrips)
 		tstrip_t s, ns = TIFFNumberOfStrips(in);
 		uint32 row = 0;
 		_TIFFmemset(buf, 0, stripsize);
-		for (s = 0; s < ns; s++) {
+		for (s = 0; s < ns && row < imagelength; s++) {
 			tsize_t cc = (row + rowsperstrip > imagelength) ?
 			    TIFFVStripSize(in, imagelength - row) : stripsize;
 			if (TIFFReadEncodedStrip(in, s, buf, cc) < 0