[PATCH security-next v4 23/32] selinux: Remove boot parameter

[Jordan Glover]

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, October 2, 2018 4:57 PM, Stephen Smalley <sds at tycho.nsa.gov> wrote:

> On 10/02/2018 10:44 AM, Kees Cook wrote:
>
> > On Tue, Oct 2, 2018 at 6:42 AM, Stephen Smalley sds at tycho.nsa.gov wrote:
> >
> > > On 10/02/2018 08:12 AM, Paul Moore wrote:
> > >
> > > > On Mon, Oct 1, 2018 at 9:04 PM Kees Cook keescook at chromium.org wrote:
> > > >
> > > > > Since LSM enabling is now centralized with CONFIG_LSM_ENABLE and
> > > > > "lsm.enable=...", this removes the LSM-specific enabling logic from
> > > > > SELinux.
> > > > >
> > > > > Signed-off-by: Kees Cook keescook at chromium.org
> > > > >
> > > > > -----------------------------------------------
> > > > >
> > > > > .../admin-guide/kernel-parameters.txt | 9 ------
> > > > > security/selinux/Kconfig | 29 -------------------
> > > > > security/selinux/hooks.c | 15 +---------
> > > > > 3 files changed, 1 insertion(+), 52 deletions(-)
> > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt
> > > > > b/Documentation/admin-guide/kernel-parameters.txt
> > > > > index cf963febebb0..0d10ab3d020e 100644
> > > > > --- a/Documentation/admin-guide/kernel-parameters.txt
> > > > > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > > > > @@ -4045,15 +4045,6 @@
> > > > > loaded. An invalid security module name will be
> > > > > treated
> > > > > as if no module has been chosen.
> > > > >
> > > > > -         selinux=        [SELINUX] Disable or enable SELinux at boot time.
> > > > >
> > > > >
> > > > > -                         Format: { "0" | "1" }
> > > > >
> > > > >
> > > > > -                         See security/selinux/Kconfig help text.
> > > > >
> > > > >
> > > > > -                         0 -- disable.
> > > > >
> > > > >
> > > > > -                         1 -- enable.
> > > > >
> > > > >
> > > > > -                         Default value is set via kernel config option.
> > > > >
> > > > >
> > > > > -                         If enabled at boot time, /selinux/disable can be
> > > > >
> > > > >
> > > > >
> > > > > used
> > > > >
> > > > > -                         later to disable prior to initial policy load.
> > > > >
> > > > >
> > > >
> > > > No comments yet on the rest of the patchset, but the subject line of
> > > > this patch caught my eye and I wanted to comment quickly on this one
> > > > ...
> > > > Not a fan unfortunately.
> > > > Much like the SELinux bits under /proc/self/attr, this is a user
> > > > visible thing which has made its way into a lot of docs, scripts, and
> > > > minds; I believe removing it would be a big mistake.
> > >
> > > Yes, we can't suddenly break existing systems that had selinux=0 in their
> > > grub config. We have to retain the support.
> >
> > Is it okay to only support selinux=0 (instead of also selinux=1)?
>
> For Fedora/RHEL kernels, selinux=1 would be redundant since it is the
> default. However, in other distros where SELinux is not the default, I
> think they have documented selinux=1 as the way to enable SELinux. So
> users may be relying on that as well. I don't think we can safely drop
> support for either one. Sorry.

It's always documented as: "selinux=1 security=selinux" so security= should
still do the job and selinux=1 become no-op, no?

Jordan