Messages in this thread | | | Date | Fri, 18 May 2007 16:19:56 +0300 | From | "Ahmed S. Darwish" <> | Subject | Re: Fork Bombing Attack |
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On 5/18/07, Anand Jahagirdar <anandjigar@gmail.com> wrote: > Hello All > I tried to execute a program which creates 8152 process.( > i=0; while( i<14) i++ fork(); ) with ulimit 8200. This program > created 8152 processes and then stopped and came back to command > prompt. this proves that my machine do have sufficient resources to > create 8000 processes. > > I found one more interesting thing on the same machine > having FC6 distribution and Linux Kernel 2.6.18. i have set "ulimit -u > 100". after setting this limit i tried to execute fork bombing program > with guest account. after executing it > > expected result:- guest uesr should not able to fork another single > process when it reaches to 100 processes count. > > actual result :- kernel allow me to create another processes without > giving error. due to this i tried to execute same fork bombing program > on another terminal with guest account and this fork bombing attack > killed the box completely and machine needed reboot. >
I think if you want resource limiting per _UID_ (and not per _process_ as you did), you should use PAM module pam_limits.so. You can edit those limits using the file /etc/security/limits.conf
Regards, -- Ahmed S. Darwish http://darwish-07.blogspot.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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