http://svn.php.net/viewvc?view=revision&revision=288943

--- ext/posix/posix.c	2009-10-20 08:12:27.000000000 -0400
+++ ext/posix/posix.c.oden	2009-10-20 08:12:40.000000000 -0400
@@ -678,7 +678,8 @@ PHP_FUNCTION(posix_mkfifo)
 		RETURN_FALSE;
 	}
 
-	if (PG(safe_mode) && (!php_checkuid(path, NULL, CHECKUID_ALLOW_ONLY_DIR))) {
+	if (php_check_open_basedir_ex(path, 0 TSRMLS_CC) ||
+			(PG(safe_mode) && (!php_checkuid(path, NULL, CHECKUID_ALLOW_ONLY_DIR)))) {
 		RETURN_FALSE;
 	}