Limit ROM size to 32 MiB.

Limit the utilLoad() function in src/Util.cpp to 32 MiB.

This function loads a file from disk and returns a memory image of it.

This is only used to load ROMs currently.

src/Util.cpp

@@ -60,6 +60,8 @@ static int(ZEXPORT *utilGzReadFunc)(gzFile, voidp, unsigned int) = NULL;
 static int(ZEXPORT *utilGzCloseFunc)(gzFile) = NULL;
 static z_off_t(ZEXPORT *utilGzSeekFunc)(gzFile, z_off_t, int) = NULL;
 
+#define MAX_CART_SIZE 0x2000000 // 32MB
+
 bool FileExists(const char *filename)
 {
 #ifdef _WIN32
@@ -586,6 +588,9 @@ uint8_t *utilLoad(const char *file, bool (*accept)(const char *), uint8_t *data,
         if (size == 0)
                 size = fileSize;
 
+        if (size > MAX_CART_SIZE)
+                return NULL;
+        
         uint8_t *image = data;
 
         if (image == NULL) {