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From: Stephen Boyd <swboyd@chromium.org>
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Date: Tue, 21 May 2024 00:14:08 -0400
Message-ID: <CAE-0n50TuoSEaWmAcUoX3KDtp2ivdHmqWpaYn+dVdo4_L1H2NA@mail.gmail.com>
Subject: Re: [PATCH] loadpin: Prevent SECURITY_LOADPIN_ENFORCE=y without
 module decompression
To: Kees Cook <keescook@chromium.org>
Cc: Paul Moore <paul@paul-moore.com>, James Morris <jmorris@namei.org>, 
	"Serge E . Hallyn" <serge@hallyn.com>, linux-kernel@vger.kernel.org, patches@lists.linux.dev, 
	linux-security-module@vger.kernel.org, 
	Dmitry Torokhov <dmitry.torokhov@gmail.com>, Douglas Anderson <dianders@chromium.org>
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Quoting Kees Cook (2024-05-18 13:47:14)
> On Tue, May 14, 2024 at 03:48:38PM -0700, Stephen Boyd wrote:
> > If modules are built compressed, and LoadPin is enforcing by default, we
> > must have in-kernel module decompression enabled (MODULE_DECOMPRESS).
> > Modules will fail to load without decompression built into the kernel
> > because they'll be blocked by LoadPin. Add a depends on clause to
> > prevent this combination.
> >
> > Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > Cc: Douglas Anderson <dianders@chromium.org>
> > Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> > ---
> >  security/loadpin/Kconfig | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/security/loadpin/Kconfig b/security/loadpin/Kconfig
> > index 6724eaba3d36..8c22171088a7 100644
> > --- a/security/loadpin/Kconfig
> > +++ b/security/loadpin/Kconfig
> > @@ -14,6 +14,9 @@ config SECURITY_LOADPIN
> >  config SECURITY_LOADPIN_ENFORCE
> >       bool "Enforce LoadPin at boot"
> >       depends on SECURITY_LOADPIN
> > +     # Module compression breaks LoadPin unless modules are decompressed in
> > +     # the kernel.
> > +     depends on MODULE_COMPRESS_NONE || MODULE_DECOMPRESS
> >       help
> >         If selected, LoadPin will enforce pinning at boot. If not
> >         selected, it can be enabled at boot with the kernel parameter
> >
>
> I've folded this change in, since loadpin also works in non-module
> situations:

Thanks for fixing my thinko.