Re: [PATCH 2/2] AppArmor: Fix masking of capabilities in complain mode

Greg KH
2011-06-29T15:16:09Z

On Wed, Jun 29, 2011 at 08:55:18AM +0100, John Johansen wrote:
> On 06/29/2011 05:24 AM, Greg KH wrote:
> > On Wed, Jun 29, 2011 at 02:44:34AM +0100, John Johansen wrote:
> >> AppArmor is masking the capabilities returned by capget against the
> >> capabilities mask in the profile. This is wrong, in complain mode the
> >> profile has effectively all capabilities, as the profile restrictions are
> >> not being enforced, merely tested against to determine if an access is
> >> known by the profile.
> >>
> >> This can result in the wrong behavior of security conscience applications
> >> like sshd which examine their capability set, and change their behavior
> >> accordingly. In this case because of the masked capability set being
> >> returned sshd fails due to DAC checks, even when the profile is in complain
> >> mode.
> >>
> >> Kernels affected: 2.6.36 - 3.0.
> >>
> >> Signed-off-by: John Johansen <john.johansen@canonical.com>
> >> ---
> >
> > You say that multiple kernels are affected, then why not also include
> > stable@kernel.org here as well?
> >
> > confused,
> >
> Sorry I should have elaborated, I think its a borderline case for stable
> release, and was as much a note to my self as anything.

Notes to self probably shouldn't be in kernel changelog entries :)

> The bug doesn't affect the enforcement of policy, only learning mode used
> for generating policy, and it is something we can work around in userspace.
> for already released kernels.
>
> I can resend with a Cc: stable if you would like

If you don't think it should be in the stable kernel releases, that's
fine, you are the maintainer of the code. I just found it odd that you
said it affected older kernels and yet didn't want it applied there as
well.

greg k-h