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Message-ID: <003201c448e8$df842b10$74beebd5@wbp1>
To: "Paul G" <paul@rusko.us>,
	<internals@lists.php.net>
References: <001201c448a8$4ba310e0$74beebd5@wbp1> <03b401c448a8$30086a60$0200a8c0@rusko>
Date: Wed, 2 Jun 2004 23:30:48 +0200
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Subject: Re: [PHP-DEV] virtual(),  an easy way to put Apache server in spirals down.
From: ntpt@centrum.cz ("NTPT")

I have  max execution time set to 180 and mem limit to 64 mb , there is a
3*128mb physical ram total and about 1G swap space available .

Lowering the mem limit helps a bit (take longer time and more requests
needed ), but if you do more requests  (5 - 10 at
almost same time , ie click  10* reload ), situation is the same, server
start swapping and stop almost all response, until httpd processes  are
killed by the kernel because exceeded memory limits  .....


----- Original Message ----- 
From: "Paul G" <paul@rusko.us>
To: <internals@lists.php.net>
Sent: Wednesday, June 02, 2004 3:47 PM
Subject: Re: [PHP-DEV] virtual(), an easy way to put Apache server in
spirals down.


> do you have a maximum mem restriction in your php.ini?
>
> paul
>
> ----- Original Message ----- 
> From: "NTPT" <ntpt@centrum.cz>
> To: <internals@lists.php.net>
> Sent: Wednesday, June 02, 2004 9:48 AM
> Subject: [PHP-DEV] virtual(), an easy way to put Apache server in spirals
> down.
>
>
> Hi.
>
> I think following things may be a security risk in mod_php, maybe allowing
a
> DoS attak if your server users can use  php engine for your www pages.
>
>
> If you make a file  foo.php what contains  function  virtual(), pointing
to
> itself, ie virtual(foo.php)
> at least in php 4.3.2  an infinite lop occure, that eat up all the memory
> and  swap, eat all the  resouces and script is terminated with :
>
> "failed to open stream: Limit of open files reached  "
>
> and
>
> Fatal error: Allowed memory size of 67108864 bytes exhausted at (null):0
> (tried to allocate 4260 bytes) in Unknown on line 0
>
>
> I suggest to add  a check for maximum recursion level in virtual() if
> possible and   an appropriate directive into the php.ini file that can set
> this recursion level.
>
>
> Regards, NTPT
>
> PS: please execuse my bad english
>
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