Moin, Quoting Peer-Christoph Mettelem (Peer-Christoph.Mettelem@bezreg-muenster.nrw.de) on Mon, Apr 23, 2001 at 09:48:12AM +0200:

Hi,

I just wrote a shell script which looks like this: while true do $0 done

I executed it as normal user and then the following happened: As you can imagine, very many shells were started (i wasn't able to count them because the system wasnt responding any more). And then the system started killing system processes like X and smbd. I got the following output on console 10: Apr 23 09:11:54 AlBundy kernel: VM: killing process kmail Apr 23 09:12:52 AlBundy kernel: VM: killing process smbd Apr 23 09:13:03 AlBundy kernel: VM: killing process smbd Apr 23 09:13:05 AlBundy kernel: VM: killing process xconsole Apr 23 09:13:13 AlBundy kernel: VM: killing process X

The system recovered itself by killing X. That worked because i started the script from a shell in KDE. But if the script would be started within a telnet session, it could be more dangerous.

I don't know if this is a security hole, but it might be.

This is a security hole if you ask me. Especially when seeing a non privileged user process eating up resources quickly. That should not happen, even without explicit ulimits. AIX had the same problem some yaers ago, then the changed the algorithm for killing processes in that situation and nowadays it seems to be killing the offender most of the time. Time for a kernel change me thinks. afx -- atsec information security GmbH Phone: +49-89-44249830 Steinstrasse 68 Fax: +49-89-44249831 D-81667 Muenchen, Germany WWW: www.atsec.com May the Source be with you!