Re: [PATCH] ima: add a new CONFIG for loading arch-specific policies

Mimi Zohar
2020-02-27T19:38:22Z

On Wed, 2020-02-26 at 15:36 -0500, Mimi Zohar wrote:
> On Wed, 2020-02-26 at 11:21 -0800, Lakshmi Ramasubramanian wrote:
> > Hi Nayna,
> >
> > > +
> > > +config IMA_SECURE_AND_OR_TRUSTED_BOOT
> > > + bool
> > > + depends on IMA
> > > + depends on IMA_ARCH_POLICY
> > > + default n
> > > + help
> > > + This option is selected by architectures to enable secure and/or
> > > + trusted boot based on IMA runtime policies.
> > >
> >
> > Why is the default for this new config "n"?
> > Is there any reason to not turn on this config if both IMA and
> > IMA_ARCH_POLICY are set to y?
>
> Good catch.  Having "IMA_SECURE_AND_OR_TRUSTED_BOOT" depend on
> "IMA_ARCH_POLICY" doesn't make sense.  "IMA_ARCH_POLICY" needs to be
> selected.

After discussing this some more with Nayna, the new Kconfig indicates
that the architecture defines the arch_ima_get_secureboot() and
arch_get_ima_policy() functions, but doesn't automatically enable
IMA_ARCH_POLICY.  The decision to enable IMA_ARCH_POLICY is left up to
whoever is building the kernel.  The patch, at least this aspect of
it, is correct.

Mimi