Hi,
I'm no longer subscribed to internals so I don't know if this email will show
up there. If not, feel free to forward it.
> On 17 Apr 2015, at 17:43, Ferenc Kovacs <tyr...@gmail.com> wrote:
>
>
>
>> On Fri, Apr 17, 2015 at 6:11 PM, Julien Pauli <jpa...@php.net> wrote:
>> Just a simple use case showing how dangerous that is :
>>
>> <?php
>> $p = function($p) { $this->$p = new Stdclass; };
>> $p->call($e = new Exception, 'trace');
>> throw $e;
>>
>>
>> That nearly crashes PHP7.
>> http://3v4l.org/fJj22
>>
>> (The same trick using Reflection with PHP5 crashes the engine, this is a
>> known bug that we chose not to fix).
>>
>>
>> I am absolutely not confident at all having Closure::call() beeing able to
>> access private data.
>>
>> Private is private.
>>
>> For internal classes, this is even worse, and could lead to crash (look at
>> the example about Exception).
>> Changing a variable that is private, is absolutely NOT expected from the
>> class designer.
>>
>> For User classes, this could lead to information leaks or bad behaviors,
>> and for internal classes this is even worse and could easilly segfault or
>> with a little bit of more magic and brain sauce, lead to memory disclosures.
>>
>> I would like we re-open the debate about accessign private data with
>> external code (closure), especially in a write context.
>>
>>
>> Julien.P
>
> For the record this isn't exclusive to Closure::call, afaik the same thing is
> possible with Closure::bind() since 5.4
> http://3v4l.org/hlFS4
> And there are/were a decent amount of discussion (and AFAIR even hydrate
> libraries using this trick) about this, for example:
> http://ocramius.github.io/blog/accessing-private-php-class-members-without-reflection/
> So while I think that for 7.0 we could remove this behavior, the cat is
> already out of the bag, as you can see from my paste you can use that code to
> cause segfaults for php >=5.4.0, so I think it would be better to fix the
> internal classes to properly handle/validate their properties instead of
> blindly trusting their types.
Right, what Closure::call() does isn't particularly new. I'm not sure if it's a
good thing that you can arbitrarily re-scope closures, but that's how it is.
Also, if information leaks are a worry, we've had things like ob_start() and
var_dump(), and (array) for a while now.
A further thought: type hints for class properties would be helpful here.
Thanks.
--
Andrea Faulds
http://ajf.me/
