--- cups-1.3.7/filter/image-png.c.orig	2007-07-11 23:46:42.000000000 +0200
+++ cups-1.3.7/filter/image-png.c	2008-04-16 12:04:14.000000000 +0200
@@ -170,16 +170,56 @@
     * Interlaced images must be loaded all at once...
     */
 
+    size_t bufsize;			/* Size of buffer */
+
+
     if (color_type == PNG_COLOR_TYPE_GRAY ||
 	color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-      in = malloc(img->xsize * img->ysize);
+    {
+      bufsize = img->xsize * img->ysize;
+
+      if ((bufsize / img->ysize) != img->xsize)
+      {
+	fprintf(stderr, "DEBUG: PNG image dimensions (%ux%u) too large!\n",
+		(unsigned)width, (unsigned)height);
+	fclose(fp);
+	return (1);
+      }
+    }
     else
-      in = malloc(img->xsize * img->ysize * 3);
+    {
+      bufsize = img->xsize * img->ysize * 3;
+
+      if ((bufsize / (img->ysize * 3)) != img->xsize)
+      {
+	fprintf(stderr, "DEBUG: PNG image dimensions (%ux%u) too large!\n",
+		(unsigned)width, (unsigned)height);
+	fclose(fp);
+	return (1);
+      }
+    }
+
+    in = malloc(bufsize);
   }
 
   bpp = cupsImageGetDepth(img);
   out = malloc(img->xsize * bpp);
 
+  if (!in || !out)
+  {
+    fputs("DEBUG: Unable to allocate memory for PNG image!\n", stderr);
+
+    if (in)
+      free(in);
+
+    if (out)
+      free(out);
+
+    fclose(fp);
+
+    return (1);
+  }
+
  /*
   * Read the image, interlacing as needed...
   */