From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 231F2C433DF for ; Fri, 31 Jul 2020 21:07:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F10DD2087C for ; Fri, 31 Jul 2020 21:07:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=defensec.nl header.i=@defensec.nl header.b="WawwyQKR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728015AbgGaVHW (ORCPT ); Fri, 31 Jul 2020 17:07:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726884AbgGaVHW (ORCPT ); Fri, 31 Jul 2020 17:07:22 -0400 Received: from agnus.defensec.nl (agnus.defensec.nl [IPv6:2001:985:d55d::711]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4C3F4C061574 for ; Fri, 31 Jul 2020 14:07:22 -0700 (PDT) Received: from brutus (brutus.lan [IPv6:2001:985:d55d::438]) by agnus.defensec.nl (Postfix) with ESMTPSA id 613B62A1003; Fri, 31 Jul 2020 23:07:21 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 agnus.defensec.nl 613B62A1003 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=defensec.nl; s=default; t=1596229641; bh=BgdXX8kQ56iUMK6yh9Mb/ejP74Ty7qfgKYm9cd0o1V0=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=WawwyQKRozKDQ61b0TVkkPg/GT8mrqzqGZ9IbH6EbL4mKnjYFLf+Z0TAcnKHM39R1 Na0b8v/F9Yc9HXy5Vzdt2NzEkaVzI78tHnxc7yMU4hcXihBh8mpGa9z6jnLLjHCSZV D7DoNLoUzZjZQ9FUVY19+ufEDn5+1mSyYaAp5iS8= From: Dominick Grift To: James Carter Cc: SElinux list Subject: Re: [PATCH v3] secilc/docs: document expandtypeattribute References: <20200730114555.915996-1-dominick.grift@defensec.nl> <20200730131149.928220-1-dominick.grift@defensec.nl> Date: Fri, 31 Jul 2020 23:07:17 +0200 In-Reply-To: (James Carter's message of "Fri, 31 Jul 2020 16:22:44 -0400") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: selinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org James Carter writes: > On Fri, Jul 31, 2020 at 4:12 PM Dominick Grift > wrote: >> >> James Carter writes: >> >> > On Fri, Jul 31, 2020 at 3:26 AM Dominick Grift >> > wrote: >> >> >> >> James Carter writes: >> >> >> >> > On Thu, Jul 30, 2020 at 9:14 AM Dominick Grift >> >> > wrote: >> >> >> >> >> >> This was added for Androids Treble in 2017. >> >> >> >> >> >> I was unsure whether this belongs in type_statements or in conditional_statements. >> >> >> >> >> > >> >> > I think that it fits best with the type statements as you have it. >> >> > >> >> >> Signed-off-by: Dominick Grift >> >> >> --- >> >> >> v2: overriden is overridden >> >> >> v3: add link to README.md >> >> >> >> >> >> secilc/docs/README.md | 1 + >> >> >> secilc/docs/cil_type_statements.md | 38 ++++++++++++++++++++++++++++++ >> >> >> 2 files changed, 39 insertions(+) >> >> >> >> >> >> diff --git a/secilc/docs/README.md b/secilc/docs/README.md >> >> >> index 3f1838e6..efab2a71 100644 >> >> >> --- a/secilc/docs/README.md >> >> >> +++ b/secilc/docs/README.md >> >> >> @@ -126,6 +126,7 @@ CIL (Common Intermediate Language) >> >> >> * [typealiasactual](cil_type_statements.md#typealiasactual) >> >> >> * [typeattribute](cil_type_statements.md#typeattribute) >> >> >> * [typeattributeset](cil_type_statements.md#typeattributeset) >> >> >> + * [expandtypeattribute](cil_type_statements.md#expandtypeattribute) >> >> >> * [typebounds](cil_type_statements.md#typebounds) >> >> >> * [typechange](cil_type_statements.md#typechange) >> >> >> * [typemember](cil_type_statements.md#typemember) >> >> >> diff --git a/secilc/docs/cil_type_statements.md b/secilc/docs/cil_type_statements.md >> >> >> index f9dd3a76..f819b3c6 100644 >> >> >> --- a/secilc/docs/cil_type_statements.md >> >> >> +++ b/secilc/docs/cil_type_statements.md >> >> >> @@ -213,6 +213,44 @@ This example is equivalent to `{ domain -kernel.process -ueventd.process -init.p >> >> >> ) >> >> >> ) >> >> >> >> >> >> +expandtypeattribute >> >> >> +------------------- >> >> >> + >> >> >> +Allows expansion compiler defaults for one or more previously declared [`typeattribute`](cil_type_statements.md#typeattribute) identifiers to be overridden. >> >> > >> >> > The wording confused me at first. >> >> > I think "Overrides the compiler defaults for the expansion of one ... >> >> > identifiers." would be clearer. >> >> > >> >> >> + >> >> >> +**Statement definition:** >> >> >> + >> >> >> + (expandtypeattribute typeattribute_id true|false) >> >> >> + >> >> >> +**Where:** >> >> >> + >> >> >> + >> >> >> +>> >> >> +>> >> >> +>> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> + >> >> >> +

expandtypeattribute

The expandtypeattribute keyword.

typeattribute_id

One or more previously declared typeattribute identifiers.

true | false

Either true or false.

>> >> >> + >> >> >> +**Example:** >> >> >> + >> >> >> +This example will use the expandtypeattribute statement to forcibly expand a previously declared `domain` type attribute. >> >> >> + >> >> >> + (expandtypeattribute domain true) >> >> >> + >> >> > >> >> > It would be nice to have another example that shows a list of type >> >> > attributes, so there is an example of that syntax as well. >> >> >> >> I was looking into an example but turns out that either i am >> >> misunderstanding this functionality or that it does not work as advertised: >> >> >> >> Example: >> >> >> >> 1. compiler defaults to expand typeattributes with less >> >> than four members >> >> 2. override pets and dogs expansion in policy >> >> >> >> # cat > mytest.cil <> >> (sid mysid) >> >> (sidorder (mysid)) >> >> >> >> (class myclass (mypermission)) >> >> (classorder (unordered myclass)) >> >> >> >> (type blue) >> >> (type green) >> >> (type red) >> >> (typeattribute colors) >> >> (typeattributeset colors (blue green red)) >> >> >> >> (type dog) >> >> (type cat) >> >> (type goldfish) >> >> (typeattribute pets) >> >> (typeattributeset pets (dog cat goldfish)) >> >> >> >> (dontaudit pets colors (myclass (mypermission))) >> >> >> >> (expandtypeattribute (colors pets) false) >> >> EOF >> >> >> >> # secilc -v -X 4 mytest.cil >> >> # sesearch policy.32 --dontaudit >> >> >> > >> > The key is that expandtypeattribute works differently for the default >> > behavior than when you ask for attributes to be expanded. >> > >> > The default rules for removing attributes are complex. In general, >> > attributes automatically created when converting a binary module to >> > CIL; attributes that are not used in allow and dontaudit rules; and >> > attributes that have only one type assigned are all removed. This >> > means that the attribute rule and the typeattributeset rules for the >> > attribute are removed and all rules using the attribute are expanded. >> > Using expandtypeattribute in this case will keep the attribute >> > declaration, the typeattributeset rules, and any allow rules. >> > >> > When you use "-X SIZE" all allow rules with attributes that contain >> > less than SIZE types will be expanded and the attribute removed. Using >> > expandtypeattribute in this case will cause the attribute declaration >> > and the typeattributeset rules to be retained, but the allow rules >> > will still be expanded. >> > >> > I just verified that everything does work like that. >> > >> > It is a bit of a mess, but it is working as intended. >> > >> > I probably need to document how the default expansion works. ;) >> >> >> So that makes the "false" scenario practically irrelevant? when would >> one ever use "false" instead of "true"? >> > > That is actually the most valuable option. It is the way to ensure > that an attribute definition is not removed. It is being used, for > example, by Google to keep attributes that are used in the neverallow > rules in their compatibility test suite from being expanded. Good thing it is friday. I think i need to sleep on this a couple of day's and see if I can make some sense out of all of this. > > Jim > >> > >> > Thanks, >> > Jim >> > >> > >> >> > >> >> > Thanks for doing this. >> >> > Jim >> >> > >> >> >> typebounds >> >> >> ---------- >> >> >> >> >> >> -- >> >> >> 2.28.0.rc1 >> >> >> >> >> >> >> -- >> >> gpg --locate-keys dominick.grift@defensec.nl >> >> Key fingerprint = FCD2 3660 5D6B 9D27 7FC6 E0FF DA7E 521F 10F6 4098 >> >> https://sks-keyservers.net/pks/lookup?op=get&search=0xDA7E521F10F64098 >> >> Dominick Grift >> >> -- >> gpg --locate-keys dominick.grift@defensec.nl >> Key fingerprint = FCD2 3660 5D6B 9D27 7FC6 E0FF DA7E 521F 10F6 4098 >> https://sks-keyservers.net/pks/lookup?op=get&search=0xDA7E521F10F64098 >> Dominick Grift -- gpg --locate-keys dominick.grift@defensec.nl Key fingerprint = FCD2 3660 5D6B 9D27 7FC6 E0FF DA7E 521F 10F6 4098 https://sks-keyservers.net/pks/lookup?op=get&search=0xDA7E521F10F64098 Dominick Grift