Messages in this thread | | | Date | Sun, 26 May 2013 11:23:01 -0700 | From | Casey Schaufler <> | Subject | Re: Stupid VFS name lookup interface.. |
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On 5/26/2013 5:02 AM, Theodore Ts'o wrote: > On Sat, May 25, 2013 at 11:33:46AM -0700, Casey Schaufler wrote: >> Now I'll put on my Smack maintainer hat. Performance improvement is >> always welcome, but I would rather see attention to performance of >> the LSM architecture than SELinux specific hacks. The LSM blob >> pointer scheme is there so that you (Linus) don't have to see the >> dreadful things that we security people are doing. Is it time to >> get past that level of disassociation? Or, and I really hate asking >> this, have you fallen into the SELinux camp? > What part of the LSM architecture are you proposing be optimized?
Secids are an inherent performance issue.
This thread is all about a performance problem with the security blob pointer scheme. I don't know what would be better and general, but I'm willing to learn.
> The > LSM layer is pretty thin, partially because the various different > security approaches don't agree with each other on fairly fundamental > issues. What sort of optimization opportunities you are suggesting? > Are there changes that can be made that all of the major security LSM > maintainers would actually agree with?
As you point out, the various existing LSMs use a variety of mechanisms to perform their access checks. A big part of what I see as the "problem" is that the LSM hooks grew organically, at a time when there was exactly one project being funded. By the time other LSMs came in to the mainstream we had a collection of hooks, not an architecture. The LSM architecture has not been seriously revisited since.
Can we come to agreement? I don't know. I expect so.
> > I've been re-reading the thread on LKML which was spawned when SMACK > was proposed for upstream inclusion: > > http://thread.gmane.org/gmane.linux.kernel/585903/focus=586412 > > Have any of the arguments over the proper security models changed over > or have gotten resolved over the past six years, while I haven't been > looking?
I believe that Yama points to a serious change in the way "operating systems" are being developed. The desktop is not the sweet spot for Linux development, nor is the enterprise server. Six years ago the Bell & LaPadula subject/object models still made sense. Today, we're looking at applications, services and resources. We don't have LSMs that support those* natively. We are going to have new LSMs, and soon, if Linux is going to remain relevant.
--- * SEAndriod is trying. We'll see where that goes.
> > - Ted >
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