ocaml-camlimages/camlimages-oversized-png-ch...

82 lines
2.4 KiB
Diff

--- camlimages-3.0.1.orig/src/pngread.c 2007-01-18 10:29:57.000000000 +0000
+++ camlimages-3.0.1.oversized/src/pngread.c 2009-07-03 15:51:00.000000000 +0100
@@ -15,6 +15,8 @@
#include "config.h"
#endif
+#include <limits.h>
+
#include <png.h>
#include <caml/mlvalues.h>
@@ -26,6 +28,12 @@
#define PNG_TAG_INDEX16 2
#define PNG_TAG_INDEX4 3
+/* Test if x or y are negative, or if multiplying x * y would cause an
+ * arithmetic overflow.
+ */
+#define oversized(x, y) \
+ ((x) < 0 || (y) < 0 || ((y) != 0 && (x) > INT_MAX / (y)))
+
value read_png_file_as_rgb24( name )
value name;
{
@@ -81,6 +89,9 @@
png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
&interlace_type, NULL, NULL);
+ if (oversized (width, height))
+ failwith ("png error: image contains oversized or bogus width and height");
+
if ( color_type == PNG_COLOR_TYPE_GRAY ||
color_type == PNG_COLOR_TYPE_GRAY_ALPHA ) {
png_set_gray_to_rgb(png_ptr);
@@ -102,10 +113,16 @@
rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+ if (oversized (rowbytes, height))
+ failwith ("png error: image contains oversized or bogus rowbytes and height");
+
{
int i;
png_bytep *row_pointers;
+ if (oversized (sizeof (png_bytep), height))
+ failwith ("png error: image contains oversized or bogus height");
+
row_pointers = (png_bytep*) stat_alloc(sizeof(png_bytep) * height);
res = alloc_tuple(3);
@@ -235,6 +252,9 @@
png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
&interlace_type, NULL, NULL);
+ if (oversized (width, height))
+ failwith ("png error: image contains oversized or bogus width and height");
+
if ( color_type == PNG_COLOR_TYPE_GRAY ||
color_type == PNG_COLOR_TYPE_GRAY_ALPHA ) {
png_set_gray_to_rgb(png_ptr);
@@ -251,6 +271,9 @@
rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+ if (oversized (rowbytes, height))
+ failwith ("png error: image contains oversized or bogus rowbytes and height");
+
/*
fprintf(stderr, "pngread.c: actual loading\n"); fflush(stderr);
*/
@@ -259,6 +282,9 @@
png_bytep *row_pointers;
char mesg[256];
+ if (oversized (sizeof (png_bytep), height))
+ failwith ("png error: image contains oversized or bogus height");
+
row_pointers = (png_bytep*)stat_alloc(sizeof(png_bytep) * height);
res = alloc_tuple(3);