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authorNicolas Pena <npm@chromium.org>2017-01-25 10:41:06 -0500
committerChromium commit bot <commit-bot@chromium.org>2017-01-25 23:25:22 +0000
commit4fc34fa8376dd5cd119606ba6e0dd7e08d23ac38 (patch)
treebe0bdf1785d6131285d9f627cea1e1150385438b /third_party/libtiff/tif_getimage.c
parent03de88464cc818ac4353de3e7ec49b98166bcdc5 (diff)
downloadpdfium-4fc34fa8376dd5cd119606ba6e0dd7e08d23ac38.tar.xz
Prevent skew overflows in gtTileContig
Using int64 to check whether uint32 operations have overflowed. BUG=681300 Change-Id: I4470d34f2e5e61c0bf96f1c8587cdb7805afe87b Reviewed-on: https://pdfium-review.googlesource.com/2355 Reviewed-by: Tom Sepez <tsepez@chromium.org> Commit-Queue: Nicolás Peña <npm@chromium.org>
Diffstat (limited to 'third_party/libtiff/tif_getimage.c')
-rw-r--r--third_party/libtiff/tif_getimage.c45
1 files changed, 40 insertions, 5 deletions
diff --git a/third_party/libtiff/tif_getimage.c b/third_party/libtiff/tif_getimage.c
index 2861cdd1e2..5ed1b7a370 100644
--- a/third_party/libtiff/tif_getimage.c
+++ b/third_party/libtiff/tif_getimage.c
@@ -31,6 +31,7 @@
*/
#include "tiffiop.h"
#include <stdio.h>
+#include <limits.h>
static int gtTileContig(TIFFRGBAImage*, uint32*, uint32, uint32);
static int gtTileSeparate(TIFFRGBAImage*, uint32*, uint32, uint32);
@@ -612,6 +613,7 @@ gtTileContig(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
uint32 tw, th;
unsigned char* buf;
int32 fromskew, toskew;
+ int64 safeskew;
uint32 nrow;
int ret = 1, flip;
uint32 this_tw, tocol;
@@ -631,19 +633,37 @@ gtTileContig(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
flip = setorientation(img);
if (flip & FLIP_VERTICALLY) {
y = h - 1;
- toskew = -(int32)(tw + w);
+ safeskew = 0;
+ safeskew -= tw;
+ safeskew -= w;
}
else {
y = 0;
- toskew = -(int32)(tw - w);
+ safeskew = 0;
+ safeskew -= tw;
+ safeskew +=w;
}
+ if(safeskew > INT_MAX || safeskew < INT_MIN){
+ _TIFFfree(buf);
+ TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "Invalid skew");
+ return (0);
+ }
+ toskew = safeskew;
+
/*
* Leftmost tile is clipped on left side if col_offset > 0.
*/
leftmost_fromskew = img->col_offset % tw;
leftmost_tw = tw - leftmost_fromskew;
- leftmost_toskew = toskew + leftmost_fromskew;
+ safeskew = toskew;
+ safeskew += leftmost_fromskew;
+ if(safeskew > INT_MAX || safeskew < INT_MIN){
+ _TIFFfree(buf);
+ TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "Invalid skew");
+ return (0);
+ }
+ leftmost_toskew = safeskew;
for (row = 0; row < h; row += nrow)
{
rowstoread = th - (row + img->row_offset) % th;
@@ -668,9 +688,24 @@ gtTileContig(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
/*
* Rightmost tile is clipped on right side.
*/
- fromskew = tw - (w - tocol);
+ safeskew = tw;
+ safeskew -= w;
+ safeskew += tocol;
+ if(safeskew > INT_MAX || safeskew < INT_MIN){
+ _TIFFfree(buf);
+ TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "Invalid skew");
+ return (0);
+ }
+ fromskew = safeskew;
this_tw = tw - fromskew;
- this_toskew = toskew + fromskew;
+ safeskew = toskew;
+ safeskew += fromskew;
+ if(safeskew > INT_MAX || safeskew < INT_MIN){
+ _TIFFfree(buf);
+ TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "Invalid skew");
+ return (0);
+ }
+ this_toskew = safeskew;
}
(*put)(img, raster+y*w+tocol, tocol, y, this_tw, nrow, fromskew, this_toskew, buf + pos);
tocol += this_tw;