Re: LSM conversion to static interface

From: Valdis . Kletnieks
Date: Thu Oct 25 2007 - 06:23:35 EST


On Tue, 23 Oct 2007 10:34:09 CDT, "Serge E. Hallyn" said:

> And he will still be able to *run* the suid binary, but if cap_bound is
> reduced he won't be able to use capabilities taken out of the bounding
> set, multiadm loaded or not.

I am willing to bet that there's still a *lot* of unaudited set[ug]id code
out there that's vulnerable to the same sorts of attacks as the one that
hit Sendmail a few back. As such, I have to agree with your original
post of the patch that CAP_SYS_ADMIN should be required to lower the set,
as there's just too much danger of an exploit if users can create their
own reduced-set processes.

I'm debating whether we should have a printk if we detect that a removed
capability caused an -EPERM. Yes, it can be used to spam the logs. On the
other hand, I as the sysadmin would like to know if it's happening. Looks like
time for a sysctl or something....

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