Re: dynamic allocation problem in linux => DoS for all

Oliver Xymoron (oxymoron@waste.org)
Sat, 11 Sep 1999 14:39:55 -0500 (CDT)


On Sat, 11 Sep 1999, Victor STANESCU wrote:

> The problem affects a Redhat 6.0 (glibc 2.1) and a Slackware 3.6
> (libc.so.5) , tested both with 2.0.36 and 2.2.5 kernels.

The problem affects just about all systems with virtual memory that don't
have fascist policy defaults. It's called overcommit, and it's usually a
good thing.

To turn on limits, set them at login time, perhaps with the PAM limits
module.

By the way, limits are not enough to guarantee safety if (number of users)
x (user rlimit) > (ram + swap). Think on that a while to see why the
kernel doesn't have a policy.

--
 "Love the dolphins," she advised him. "Write by W.A.S.T.E.." 

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