Re: [2.6 patch] remove securebits

[Adrian Bunk <bunk@kernel.org>]

On Mon, Aug 27, 2007 at 10:28:17AM -0500, Serge E. Hallyn wrote:
> Quoting Adrian Bunk (bunk@kernel.org):
> > On Mon, Aug 27, 2007 at 10:09:42AM -0500, Serge E. Hallyn wrote:
> > > Quoting Adrian Bunk (bunk@kernel.org):
> > > > On Fri, Aug 24, 2007 at 08:50:10PM -0700, Andrew Morgan wrote:
> > > > > 
> > > > > FWIW, in the mm kernel, I've actually already removed them when one
> > > > > configures without capabilities.
> > > > > 
> > > > > http://www.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.23-rc3/2.6.23-rc3-mm1/broken-out/v3-file-capabilities-alter-behavior-of-cap_setpcap.patch
> > > > > 
> > > > > Other than writing a custom module, so far as I can tell, there is/was
> > > > > no way to set them anyway.
> > > > > 
> > > > > I'd obviously prefer to wait for the mm-merge process to complete and
> > > > > minimize the churn in this area, but I basically agree that the bits as
> > > > > implemented are pretty useless in their current form. In a per-process
> > > > > mode (with filesystem capability support) they are much more useful...
> > > > 
> > > > It was in the tree for nine years (sic) without a single user...
> > > 
> > > That's because without file capabilities there was no way for a process
> > > to retain capabilities across exec, so not having a privileged root user
> > > was simply not workable.
> > > 
> > > > Are you only improving a dead horse, or do you also have a rider for the 
> > > > improved dead horse?
> > > 
> > > It will allow process trees to run with strict capabilities, without a
> > > root user which automatically gains full capabilities.  That wasn't
> > > possible without file capabilities, since there was no way for processes
> > > to retain capabilities across exec.  Now that we have file capabilities,
> > > it is feasible, and it certainly is useful.
> > 
> > I didn't question that the dead horse gets improved, but where's the 
> > rider?
> > 
> > A user of the improved securebits has to be submitted for inclusion in 
> > the kernel.
> 
> The user would be userspace...
> 
> Unless by 'the user' you actually mean the patch itself which will allow
> the setting of secure_noroot per-process.  I don't know for sure, but
> suspect Andrew might like to wait until file capabilities make it into
> and stabilize in Linus' tree before going on with that.

That's what I am talking about.

This patch should be submitted and discussed together with the changes 
Andrew has for securebits.

> -serge

cu
Adrian

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