From a1c493aa4f22f9d1a4757c05a60addc877519cea Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Thu, 15 Aug 2019 15:05:28 +0200
Subject: [PATCH] (CVE-2019-17546) RGBA interface: fix integer overflow
potentially causing write heap buffer overflow, especially on 32 bit builds.
Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=16443. Credit to
OSS Fuzz
(cherry picked from commit 4bb584a35f87af42d6cf09d15e9ce8909a839145)
---
libtiff/tif_getimage.c | 26 ++++++++++++++++++++------
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/libtiff/tif_getimage.c b/libtiff/tif_getimage.c
index ec09feaf..c6edd27c 100644
--- a/libtiff/tif_getimage.c
+++ b/libtiff/tif_getimage.c
@@ -951,16 +951,23 @@ gtStripContig(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
fromskew = (w < imagewidth ? imagewidth - w : 0);
for (row = 0; row < h; row += nrow)
{
+ uint32 temp;
rowstoread = rowsperstrip - (row + img->row_offset) % rowsperstrip;
nrow = (row + rowstoread > h ? h - row : rowstoread);
nrowsub = nrow;
if ((nrowsub%subsamplingver)!=0)
nrowsub+=subsamplingver-nrowsub%subsamplingver;
+ temp = (row + img->row_offset)%rowsperstrip + nrowsub;
+ if( scanline > 0 && temp > (size_t)(TIFF_TMSIZE_T_MAX / scanline) )
+ {
+ TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "Integer overflow in gtStripContig");
+ return 0;
+ }
if (_TIFFReadEncodedStripAndAllocBuffer(tif,
TIFFComputeStrip(tif,row+img->row_offset, 0),
(void**)(&buf),
maxstripsize,
- ((row + img->row_offset)%rowsperstrip + nrowsub) * scanline)==(tmsize_t)(-1)
+ temp * scanline)==(tmsize_t)(-1)
&& (buf == NULL || img->stoponerr))
{
ret = 0;
@@ -1053,15 +1060,22 @@ gtStripSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
fromskew = (w < imagewidth ? imagewidth - w : 0);
for (row = 0; row < h; row += nrow)
{
+ uint32 temp;
rowstoread = rowsperstrip - (row + img->row_offset) % rowsperstrip;
nrow = (row + rowstoread > h ? h - row : rowstoread);
offset_row = row + img->row_offset;
+ temp = (row + img->row_offset)%rowsperstrip + nrow;
+ if( scanline > 0 && temp > (size_t)(TIFF_TMSIZE_T_MAX / scanline) )
+ {
+ TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "Integer overflow in gtStripSeparate");
+ return 0;
+ }
if( buf == NULL )
{
if (_TIFFReadEncodedStripAndAllocBuffer(
tif, TIFFComputeStrip(tif, offset_row, 0),
(void**) &buf, bufsize,
- ((row + img->row_offset)%rowsperstrip + nrow) * scanline)==(tmsize_t)(-1)
+ temp * scanline)==(tmsize_t)(-1)
&& (buf == NULL || img->stoponerr))
{
ret = 0;
@@ -1081,7 +1095,7 @@ gtStripSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
}
}
else if (TIFFReadEncodedStrip(tif, TIFFComputeStrip(tif, offset_row, 0),
- p0, ((row + img->row_offset)%rowsperstrip + nrow) * scanline)==(tmsize_t)(-1)
+ p0, temp * scanline)==(tmsize_t)(-1)
&& img->stoponerr)
{
ret = 0;
@@ -1089,7 +1103,7 @@ gtStripSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
}
if (colorchannels > 1
&& TIFFReadEncodedStrip(tif, TIFFComputeStrip(tif, offset_row, 1),
- p1, ((row + img->row_offset)%rowsperstrip + nrow) * scanline) == (tmsize_t)(-1)
+ p1, temp * scanline) == (tmsize_t)(-1)
&& img->stoponerr)
{
ret = 0;
@@ -1097,7 +1111,7 @@ gtStripSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
}
if (colorchannels > 1
&& TIFFReadEncodedStrip(tif, TIFFComputeStrip(tif, offset_row, 2),
- p2, ((row + img->row_offset)%rowsperstrip + nrow) * scanline) == (tmsize_t)(-1)
+ p2, temp * scanline) == (tmsize_t)(-1)
&& img->stoponerr)
{
ret = 0;
@@ -1106,7 +1120,7 @@ gtStripSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
if (alpha)
{
if (TIFFReadEncodedStrip(tif, TIFFComputeStrip(tif, offset_row, colorchannels),
- pa, ((row + img->row_offset)%rowsperstrip + nrow) * scanline)==(tmsize_t)(-1)
+ pa, temp * scanline)==(tmsize_t)(-1)
&& img->stoponerr)
{
ret = 0;