From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mimi Zohar Subject: Re: [PATCH 03/27] Enforce module signatures if the kernel is locked down Date: Thu, 02 Nov 2017 17:41:21 -0400 Message-ID: <1509658881.3416.10.camel@linux.vnet.ibm.com> References: <1509650031.3507.20.camel@linux.vnet.ibm.com> <1509130095.3716.13.camel@linux.vnet.ibm.com> <150842463163.7923.11081723749106843698.stgit@warthog.procyon.org.uk> <150842465546.7923.6762214527898273559.stgit@warthog.procyon.org.uk> <20240.1509643356@warthog.procyon.org.uk> <12321.1509658211@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <12321.1509658211-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: David Howells Cc: linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, gnomes-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jforbes-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org List-Id: linux-efi@vger.kernel.org On Thu, 2017-11-02 at 21:30 +0000, David Howells wrote: > Mimi Zohar wrote: > > > By this point, IMA-appraisal has already verified the kernel module > > signature back in kernel_read_file_from_fd(), if it was required. > >  Having a key with which to verify the appended signature or requiring > > an appended signature, should not be required as well. > > I guess I don't need to put in any support for IMA here, then, and you've > taken care of it in your patchset such that it won't actually go into > module_sig_check() in that case (or will at least return immediately). Right, it would never get here if the IMA signature verification fails.  If sig_enforce is not enabled, then it will also work.  So the only case is if sig_enforced is enabled and there is no key. eg.          else if (can_do_ima_check && is_ima_appraise_enabled())                 err = 0; Mimi