Date: Sat, 10 Jul 2004 21:02:33 +0200
From: "Philippe Plantier (ayin)"
Subject: [SDL] Problems allocating large surfaces
There are problems when allocating large surfaces using SDL_CreateRGBSurface.
When, for example, we try to allocate a surface wider than 16384 pixels,
the calculation of the pitch overflows; this leads to a surface that
has the w and h flags correctly set, but whose "pixels" buffer is too
small. That may lead to heap corruption.
--- a/src/video/SDL_surface.c Sat Aug 21 04:20:00 2004 +0000
+++ b/src/video/SDL_surface.c Sat Aug 21 05:29:45 2004 +0000
@@ -52,6 +52,13 @@
SDL_Surface *screen;
SDL_Surface *surface;
+ /* Make sure the size requested doesn't overflow our datatypes */
+ /* Next time I write a library like SDL, I'll use int for size. :) */
+ if ( width > 16384 || height > 16384 ) {
+ SDL_SetError("Width or height is too large");
+ return(NULL);
+ }
+
/* Check to see if we desire the surface in video memory */
if ( video ) {
screen = SDL_PublicSurface;