Messages in this thread | | | Date | Sun, 14 Sep 2008 09:04:08 -0700 | From | "Ulrich Drepper" <> | Subject | Re: [PATCH 12/13] hrtimer: create a "timer_slack" field in the task struct |
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On Sun, Sep 14, 2008 at 8:57 AM, Pavel Machek <pavel@suse.cz> wrote: >> LD_PRELOAD and other variables are ignored in security-relevant >> contexts and environments are cleared in many situations. Sure, you > > ...but that's okay, right? You would not want passwd to inherit huge > slack specified by attacker...?
No, it's not OK. There are enough apps which are privileged and need to be handled this way. Take the X server, for instance.
] > Well, it is not too much, but... is the cost for userspace really > significant? You'd clearly want it stored in environment, not > filesystem...
You cannot really use the environment for anything meaningful. Especially for this case, you couldn't change the setting for a running process. What a fully-userlevel implementation would have to do is read the value from a file and monitor the file for changes for every new poll/select call. That's a huge cost.
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