Re: virtual(), an easy way to put Apache server in spirals down.

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 > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: http://www.php.net/unsub.php > >