Description:
------------
There're several places in Zend code where invalid (zero) pointers can be dereferenced.


1. zend_execute_API.c, zend_call_function function:

if (error) {
	zend_error(E_WARNING, "Invalid callback %s, %s", ZSTR_VAL(callable_name), error); // <-- Access to callable_name->val
	efree(error);
}
if (callable_name) { // <-- later check if callable_name is not NULL
	zend_string_release(callable_name);
}



2. zend_execute_API.c, zend_call_function function (again):

if (func->common.fn_flags & ZEND_ACC_ABSTRACT) {
	zend_throw_error(NULL, "Cannot call abstract method %s::%s()", ZSTR_VAL(func->common.scope->name), ZSTR_VAL(func->common.function_name)); // <-- Access to func->common.scope->name
	return FAILURE;
}
if (func->common.fn_flags & ZEND_ACC_DEPRECATED) {
	zend_error(E_DEPRECATED, "Function %s%s%s() is deprecated",
		func->common.scope ? ZSTR_VAL(func->common.scope->name) : "", // <-- Later check if func->common.scope is not NULL
		func->common.scope ? "::" : "",
		ZSTR_VAL(func->common.function_name));
}



3. zend_virtual_cwd.c, realpath_cache_key function:

const char *e = bucket_key + strlen(bucket_key); // <-- Access to bucket_key buffer

if (!bucket_key) { // <-- Later check if bucket_key is not NULL
	return 0;
}