Re: Linux 3.6

[Nick Bowler <nbowler@elliptictech.com>]

On 2012-10-04 09:14 -0700, Kees Cook wrote:
> On Thu, Oct 04, 2012 at 12:03:54PM -0400, Nick Bowler wrote:
> > On 2012-10-04 08:49 -0700, Kees Cook wrote:
> > > On Thu, Oct 04, 2012 at 09:35:04AM -0400, Nick Bowler wrote:
[...]
> > > > The thing that bothers me most about all this is that it's basically
> > > > impossible to see why things are failing without digging through the git
> > > > tree or posting to the mailing list (or recalling earlier mailing list
> > > > discussions about the restriction, as I vaguely do now).  You just
> > > > suddenly get "permission denied" errors when all the permissions
> > > > involved look fine.  As far as I know, the owner, group and mode of
> > > > symlinks have always been completely meaningless.  Upgrade to 3.6, and
> > > > they're suddenly meaningful in extremely non-obvious ways.
> > > 
> > > FWIW, there should have been an audit message about it in dmesg.
> > 
> > There were zero messages in the kernel log.
> > 
> >   # dmesg -C
> >   # cd /tmp
> >   # mkdir testdir
> >   # ln -s testdir testlink
> >   # chown -h nobody testlink
> >   # cd testlink
> >   cd: permission denied: testlink
> >   # dmesg
> >   (no output)
> 
> Well that's sad. :( Two situations I can think of for that:
> - the kernel wasn't build with CONFIG_AUDIT

Indeed, I do not have this option enabled.  Why would I have it?  The
description says it's for SELinux, which I do not use.

Cheers,
-- 
Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)