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Subject: Re: [PATCH v4a 8/8] module: replace the existing LSM hook in
 init_module
From:   Mimi Zohar <zohar@linux.vnet.ibm.com>
To:     Kees Cook <keescook@chromium.org>
Cc:     Paul Moore <paul@paul-moore.com>,
        linux-integrity <linux-integrity@vger.kernel.org>,
        linux-security-module <linux-security-module@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        David Howells <dhowells@redhat.com>,
        "Luis R . Rodriguez" <mcgrof@kernel.org>,
        Eric Biederman <ebiederm@xmission.com>,
        Kexec Mailing List <kexec@lists.infradead.org>,
        Andres Rodriguez <andresx7@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Jeff Vander Stoep <jeffv@google.com>,
        Casey Schaufler <casey@schaufler-ca.com>
Date:   Tue, 05 Jun 2018 17:35:13 -0400
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On Tue, 2018-06-05 at 12:45 -0700, Kees Cook wrote:

> And if you must have a separate enum, please change this to fail
> closed instead of open (and mark the fall-through):
> 
> int rc = -EPERM;
> 
> switch (id) {
> case LOADING_MODULE:
>     rc = loadpin_read_file(NULL, READING_MODULE);
>     /* Fall-through */
> default:
>     break;
> }

This will fail the sysfs firmware fallback loading and the kexec_load
syscall without any message, as you have for init_module.  Is that
what you want?

Mimi