On Wed, Jul 23, 2014 at 11:09 AM, Ferenc Kovacs <tyr...@gmail.com> wrote: > > > > On Wed, Jul 23, 2014 at 10:57 AM, Julien Pauli <jpa...@php.net> wrote: >> >> On Wed, Jul 23, 2014 at 7:58 AM, Ferenc Kovacs <tyr...@gmail.com> wrote: >> > >> > >> > >> > On Tue, Jul 22, 2014 at 6:20 PM, Julien Pauli <jpa...@php.net> wrote: >> >> >> >> On Tue, Jul 22, 2014 at 2:04 PM, Ferenc Kovacs <tyr...@gmail.com> >> >> wrote: >> >> > >> >> > >> >> > >> >> > On Tue, Jul 22, 2014 at 1:48 PM, Nikita Popov <nikita....@gmail.com> >> >> > wrote: >> >> >> >> >> >> On Tue, Jul 22, 2014 at 12:27 PM, Ferenc Kovacs <tyr...@gmail.com> >> >> >> wrote: >> >> >>> >> >> >>> sorry for the late reply. >> >> >>> you are right and after looking into the implementation I think >> >> >>> classes >> >> >>> having custom object storage (eg. create_object) shouldn't assume >> >> >>> that >> >> >>> their __construct will be called, but either do the initialization >> >> >>> in >> >> >>> the >> >> >>> create_object hook or validate in the other methods that the object >> >> >>> was >> >> >>> properly initialized. >> >> >>> given that this lack of initialization problem is already >> >> >>> present(you >> >> >>> can >> >> >>> extend such a class and have a __construct() in the subclass which >> >> >>> doesn't >> >> >>> call the parent constructor), and we want to keep the unserialize >> >> >>> trick >> >> >>> fixed (as that exposes this problems to the remote attacker when >> >> >>> some >> >> >>> code >> >> >>> accepts arbitrary serialized data from the client) I see no reason >> >> >>> to >> >> >>> keep >> >> >>> the limitation in the >> >> >>> ReflectionClass::newInstanceWithoutConstructor() >> >> >>> and >> >> >>> allowing the instantiation of internal classes will provide a clean >> >> >>> upgrade >> >> >>> path to doctrine and co. >> >> >>> ofc. we have to fix the internal classes misusing the constructor >> >> >>> for >> >> >>> proper initialization one by one, but that can happen after the >> >> >>> initial >> >> >>> 5.6.0 release (ofc it would be wonderful if people could lend me a >> >> >>> hand >> >> >>> for >> >> >>> fixing as much as we can before the release), but we have to fix >> >> >>> those >> >> >>> anyways. >> >> >> >> >> >> >> >> >> This sounds reasonable to me. newInstanceWithoutConstructor does not >> >> >> have >> >> >> the same remote exploitation concerns as serialize, so allowing >> >> >> crashes >> >> >> here >> >> >> that can also be caused by other means seems okay to me (especially >> >> >> if >> >> >> we're >> >> >> planning to fix them lateron). Only additional restriction I'd add >> >> >> is >> >> >> to >> >> >> disallow calling it on an internal + final class. For those the >> >> >> __construct >> >> >> argument does not apply. For them the >> >> >> entity-extending-internal-class >> >> >> usecase doesn't apply either, so that shouldn't be a problem. >> >> >> >> >> >> Nikita >> >> >> >> >> > >> >> > Thanks for the prompt reply! >> >> > I was considering mentioning the final constructors, but as we >> >> > previously >> >> > didn't checked that and from a quick look it seems that we are mostly >> >> > using >> >> > it as an easy/cheap way to make sure that the object is initialized >> >> > properly >> >> > (which could also happen when a subclass calls parent::__construct() >> >> > from >> >> > it's constructor) which isn't exactly the best usecase for final. >> >> > But I don't really mind having that check. >> >> >> >> I'm +1 also with the idea. >> >> >> >> Just take care to have a clone_handler defined as well, as the default >> >> clone handler doesn't call create_object. >> >> http://lxr.php.net/xref/PHP_5_5/Zend/zend_objects.c#218 >> >> >> >> Julien >> > >> > >> > thanks, I will keep that in mind when we start moving the initialization >> > from the constructors into the create_object functions. >> > I've also went ahead and created a pull request for the proposed >> > changes: >> > https://github.com/php/php-src/pull/733 >> > as you can see I've taken Nikita's advice and internal classes with >> > final >> > constructors are still not allowed to be instantiated. >> >> When should we start patching those ? >> I guess asap ? >> >> Julien > > > Not sure, on one hand, I would be glad seeing these fixed, but on the other > hand I'm a little bit worried about introducing destabilizing changes this > close to the release, and these problems existed for years (triggerable > either through instantiating via the unserialize O: trick or through a > subclass) without any reports before https://bugs.php.net/bug.php?id=67072
Agree. We could start on a case by case basis, knowing we still got at least one RC to try that. Then anyway we're gonna fix them into next 5.6 revisions, so ... Julien.P -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
