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: Fri, 27 Oct 2017 14:48:15 -0400 Message-ID: <1509130095.3716.13.camel@linux.vnet.ibm.com> References: <150842463163.7923.11081723749106843698.stgit@warthog.procyon.org.uk> <150842465546.7923.6762214527898273559.stgit@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <150842465546.7923.6762214527898273559.stgit@warthog.procyon.org.uk> Sender: owner-linux-security-module@vger.kernel.org To: David Howells , linux-security-module@vger.kernel.org Cc: gnomes@lxorguk.ukuu.org.uk, linux-efi@vger.kernel.org, matthew.garrett@nebula.com, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, jforbes@redhat.com List-Id: linux-efi@vger.kernel.org On Thu, 2017-10-19 at 15:50 +0100, David Howells wrote: > If the kernel is locked down, require that all modules have valid > signatures that we can verify. > > Signed-off-by: David Howells > --- > > kernel/module.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/module.c b/kernel/module.c > index de66ec825992..3d9a3270c179 100644 > --- a/kernel/module.c > +++ b/kernel/module.c > @@ -2781,7 +2781,8 @@ static int module_sig_check(struct load_info *info, int flags) > } > > /* Not having a signature is only an error if we're strict. */ > - if (err == -ENOKEY && !sig_enforce) > + if (err == -ENOKEY && !sig_enforce && > + !kernel_is_locked_down("Loading of unsigned modules"))   This kernel_is_locked_down() check is being called for both the original and new module_load syscalls.  We need to be able differentiate them.  This is fine for the original syscall, but for the new syscall we would need an additional IMA check - !is_ima_appraise_enabled(). Mimi   > err = 0; > > return err;