Re: LSM stacker update

From: Serge E. Hallyn (serue@private)
Date: Tue Feb 01 2005 - 05:19:50 PST


Quoting tvrtko.ursulin@private (tvrtko.ursulin@private):
> >stacker.patch: Main change is that, since mod_reg_security()
> >actually calls verify(ops), all ops->hooks which were
> >not defined will be pointing to the dummy hooks, so
> >there is no reason to check
> >if (m)
> >m->hook();
> >so stacker now just calls m->hook().  This might provide
> >some performance improvement, particularly if the
> >m->hook call was on the path requiring the jump.  (I
> >haven't checked that).
> 
> Doesn't this break restrictive stacked hooks? For example you have two 
> modules stacked, capabilites.ko and a 3rd party one. Stacker ask 
> capability on capset_check and gets 0. Then it asks 3rd party for it, 
> which doesn't care, but dummy gets called and says -EPERM. The end result 
> is -EPERM which is not what we want.
> 
> Had been bitten by it and have a set_to_null_if_dummy in my stacker 
> register_security. :)

Compared to the last stacker patch, there should be no change in
behavior, only in performance.  But I think you're saying the
same thing Stephen is saying:  we should reconsider the calling
of verify(ops) on a mod_reg_security call.

That sounds good to me.  Does anyone disagree?

thanks,
-serge



This archive was generated by hypermail 2.1.3 : Tue Feb 01 2005 - 05:20:24 PST