* tools/tiff2rgba.c: Fix integer overflow in size of allocated

buffer, when -b mode is enabled, that could result in out-of-bounds
write. Based initially on patch tiff-CVE-2016-3945.patch from
libtiff-4.0.3-25.el7_2.src.rpm by Nikola Forro, with correction for
invalid tests that rejected valid files.

2 files changed, 39 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index 62dc1b5e..9c0ab29c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2016-08-15 Even Rouault <even.rouault at spatialys.com>
+
+	* tools/tiff2rgba.c: Fix integer overflow in size of allocated
+	buffer, when -b mode is enabled, that could result in out-of-bounds
+	write. Based initially on patch tiff-CVE-2016-3945.patch from
+	libtiff-4.0.3-25.el7_2.src.rpm by Nikola Forro, with correction for
+	invalid tests that rejected valid files.
+
 2016-07-11 Even Rouault <even.rouault at spatialys.com>
 
 	* tools/tiffcrop.c: Avoid access outside of stack allocated array
diff --git a/tools/tiff2rgba.c b/tools/tiff2rgba.c
index 7d47c940..4de96aec 100644
--- a/tools/tiff2rgba.c
+++ b/tools/tiff2rgba.c
@@ -1,4 +1,4 @@
-/* $Id: tiff2rgba.c,v 1.21 2015-06-21 01:09:10 bfriesen Exp $ */
+/* $Id: tiff2rgba.c,v 1.22 2016-08-15 20:06:41 erouault Exp $ */
 
 /*
  * Copyright (c) 1991-1997 Sam Leffler
@@ -147,6 +147,7 @@ cvt_by_tile( TIFF *in, TIFF *out )
     uint32  row, col;
     uint32  *wrk_line;
     int	    ok = 1;
+    uint32  rastersize, wrk_linesize;
 
     TIFFGetField(in, TIFFTAG_IMAGEWIDTH, &width);
     TIFFGetField(in, TIFFTAG_IMAGELENGTH, &height);
@@ -163,7 +164,13 @@ cvt_by_tile( TIFF *in, TIFF *out )
     /*
      * Allocate tile buffer
      */
-    raster = (uint32*)_TIFFmalloc(tile_width * tile_height * sizeof (uint32));
+    rastersize = tile_width * tile_height * sizeof (uint32);
+    if (tile_width != (rastersize / tile_height) / sizeof( uint32))
+    {
+	TIFFError(TIFFFileName(in), "Integer overflow when calculating raster buffer");
+	exit(-1);
+    }
+    raster = (uint32*)_TIFFmalloc(rastersize);
     if (raster == 0) {
         TIFFError(TIFFFileName(in), "No space for raster buffer");
         return (0);
@@ -173,7 +180,13 @@ cvt_by_tile( TIFF *in, TIFF *out )
      * Allocate a scanline buffer for swapping during the vertical
      * mirroring pass.
      */
-    wrk_line = (uint32*)_TIFFmalloc(tile_width * sizeof (uint32));
+    wrk_linesize = tile_width * sizeof (uint32);
+    if (tile_width != wrk_linesize / sizeof (uint32))
+    {
+        TIFFError(TIFFFileName(in), "Integer overflow when calculating wrk_line buffer");
+	exit(-1);
+    }
+    wrk_line = (uint32*)_TIFFmalloc(wrk_linesize);
     if (!wrk_line) {
         TIFFError(TIFFFileName(in), "No space for raster scanline buffer");
         ok = 0;
@@ -249,6 +262,7 @@ cvt_by_strip( TIFF *in, TIFF *out )
     uint32  row;
     uint32  *wrk_line;
     int	    ok = 1;
+    uint32  rastersize, wrk_linesize;
 
     TIFFGetField(in, TIFFTAG_IMAGEWIDTH, &width);
     TIFFGetField(in, TIFFTAG_IMAGELENGTH, &height);
@@ -263,7 +277,13 @@ cvt_by_strip( TIFF *in, TIFF *out )
     /*
      * Allocate strip buffer
      */
-    raster = (uint32*)_TIFFmalloc(width * rowsperstrip * sizeof (uint32));
+    rastersize = width * rowsperstrip * sizeof (uint32);
+    if (width != (rastersize / rowsperstrip) / sizeof( uint32))
+    {
+	TIFFError(TIFFFileName(in), "Integer overflow when calculating raster buffer");
+	exit(-1);
+    }
+    raster = (uint32*)_TIFFmalloc(rastersize);
     if (raster == 0) {
         TIFFError(TIFFFileName(in), "No space for raster buffer");
         return (0);
@@ -273,7 +293,13 @@ cvt_by_strip( TIFF *in, TIFF *out )
      * Allocate a scanline buffer for swapping during the vertical
      * mirroring pass.
      */
-    wrk_line = (uint32*)_TIFFmalloc(width * sizeof (uint32));
+    wrk_linesize = width * sizeof (uint32);
+    if (width != wrk_linesize / sizeof (uint32))
+    {
+        TIFFError(TIFFFileName(in), "Integer overflow when calculating wrk_line buffer");
+	exit(-1);
+    }
+    wrk_line = (uint32*)_TIFFmalloc(wrk_linesize);
     if (!wrk_line) {
         TIFFError(TIFFFileName(in), "No space for raster scanline buffer");
         ok = 0;