From: Casey Schaufler <casey@schaufler-ca.com>
To: Kees Cook <keescook@chromium.org>
Cc: Paul Moore <paul@paul-moore.com>,
linux-security-module <linux-security-module@vger.kernel.org>,
James Morris <jmorris@namei.org>,
LKML <linux-kernel@vger.kernel.org>,
SE Linux <selinux@tycho.nsa.gov>,
John Johansen <john.johansen@canonical.com>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Stephen Smalley <sds@tycho.nsa.gov>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
"Schaufler, Casey" <casey.schaufler@intel.com>
Subject: Re: [PATCH 10/10] LSM: Blob sharing support for S.A.R.A and LandLock
Date: Fri, 14 Sep 2018 13:47:55 -0700 [thread overview]
Message-ID: <b5601e1a-2c29-55f1-63db-01421eeaa6ea@schaufler-ca.com> (raw)
In-Reply-To: <CAGXu5jL2LjPhLsx2bQJQdj4GraTDakYTqb3fqUbWGrOfUsW8=w@mail.gmail.com>
On 9/14/2018 1:05 PM, Kees Cook wrote:
> On Fri, Sep 14, 2018 at 8:57 AM, Casey Schaufler <casey@schaufler-ca.com> wrote:
>> On 9/13/2018 5:19 PM, Kees Cook wrote:
>>> We already have the minor LSMs that cannot change order.
>> Are you saying that we don't have a mechanism to change
>> the order, or that they wouldn't work right in a different
>> order? Well, there's the capability module that has to be
>> first.
> I just meant their order is explicit in security.c.
>
>>> They aren't
>>> part of security= parsing either.
>> True, but there's no reason now that we couldn't change that.
>> Except for capability. Hmm.
> Right, we have at least one that MUST be first (and must not be disabled).
>
>>> Should "blob-sharing" LSMs be like major LSMs or minor LSMs?
>> I like the idea of changing the minor modules to do the full
>> registration process. That would make them all the same.
>> Except for capability. In any case, the "blob-sharing" LSMs
>> need to do the full registration process to account for their
>> blobs sizes, and that brings the "major" behavior along with it.
> I agree. I'm working on some clean-ups that I'll send out soon, though
> I'm worried about some of the various boot-time options...
Looking forward to seeing them.
>>> If someone is booting with "security=selinux,tomoyo" and then SARA
>>> lands upstream, does that person have to explicitly add "sara" to
>>> their boot args, since they're doing a non-default list of LSMs?
>> Yes. security= is explicit.
>>
>>> (I actually prefer the answer being "yes" here, FWIW, I just want to
>>> nail down the expectations.)
>> For now let's leave the minor (capability, yama, loadpin) as they are,
>> and require all new modules of any flavor to use full registration.
> I would even be fine to convert yama and loadpin.
That shouldn't be difficult.
>> We could consider something like
>>
>> security=$lsm # Stack with $lsm at priority 2 - Existing behavior
>> $lsm.stacked=N # Add $lsm to the stack at priority N. Delete if N == 0
>>
>> It's OK to specify "selinux.stacked=2" and "sara.stacked=2". Which gets
>> called first is left up to the system to decide. Whatever the behavior is
>> gets documented. Capability will always be first and have priority 1.
>> It's OK to specify "smack.stacked=1".
> I'm less excited about this kind of stacking priority, but, whatever
> the case, I think my cleanups may help with whatever we decide.
OK
>> The default stack is determined by CONFIG_SECURITY_$lsm_STACKED at
>> build time. CONFIG_SECURITY_$lsm_STACKED changes from a boolean to
>> an integer value to establish the default hook order.
>>
>> /sys/kernel/security/lsm reports the modules in hook call order.
> Didn't I send a patch to new-line terminate this list? I always get
> annoyed when I "cat" it. ;)
SELinux set the precedence on that one. Not my fault!
>> /sys/kernel/security/lsm-stack reports the list with the hook call priority
>>
>> capability:1,yama:1,selinux:1,sara:5,landlack:17
>>
>> If stacking is not configured $lsm.stacked=0 is treated as security=none.
>> For other values of N $lsm.stacked=N is treated as security=$lsm.
> I feel like "order" is bad enough. Can we avoid adding "priority"?
Sorry. I changed terminology (order and priority) halfway through the
message. Yes, I like order better. We should stick with that.
next prev parent reply other threads:[~2018-09-15 2:04 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-11 16:26 [PATCH v2 00/10] LSM: Module stacking in support of S.A.R.A and Landlock Casey Schaufler
2018-09-11 16:41 ` [PATCH 01/10] procfs: add smack subdir to attrs Casey Schaufler
2018-09-12 22:57 ` Kees Cook
2018-09-11 16:41 ` [PATCH 02/10] Smack: Abstract use of cred security blob Casey Schaufler
2018-09-12 23:04 ` Kees Cook
2018-09-11 16:41 ` [PATCH 03/10] SELinux: " Casey Schaufler
2018-09-12 23:10 ` Kees Cook
2018-09-11 16:41 ` [PATCH 04/10] LSM: Infrastructure management of the " Casey Schaufler
2018-09-12 23:53 ` Kees Cook
2018-09-13 19:01 ` Casey Schaufler
2018-09-13 21:12 ` Kees Cook
2018-09-11 16:41 ` [PATCH 05/10] SELinux: Abstract use of file " Casey Schaufler
2018-09-12 23:54 ` Kees Cook
2018-09-11 16:42 ` [PATCH 06/10] LSM: Infrastructure management of the " Casey Schaufler
2018-09-13 0:00 ` Kees Cook
2018-09-11 16:42 ` [PATCH 07/10] SELinux: Abstract use of inode " Casey Schaufler
2018-09-13 0:23 ` Kees Cook
2018-09-11 16:42 ` [PATCH 08/10] Smack: " Casey Schaufler
2018-09-13 0:24 ` Kees Cook
2018-09-11 16:42 ` [PATCH 09/10] LSM: Infrastructure management of the inode security Casey Schaufler
2018-09-13 0:30 ` Kees Cook
2018-09-11 16:42 ` [PATCH 10/10] LSM: Blob sharing support for S.A.R.A and LandLock Casey Schaufler
2018-09-13 4:19 ` Kees Cook
2018-09-13 13:16 ` Paul Moore
2018-09-13 15:19 ` Kees Cook
2018-09-13 19:12 ` Paul Moore
2018-09-13 20:58 ` Jordan Glover
2018-09-13 21:50 ` Paul Moore
2018-09-13 22:04 ` Jordan Glover
2018-09-13 23:01 ` Casey Schaufler
2018-09-13 21:01 ` Kees Cook
2018-09-13 21:38 ` Paul Moore
2018-09-13 21:51 ` Kees Cook
2018-09-13 23:06 ` Kees Cook
2018-09-13 23:32 ` John Johansen
2018-09-13 23:51 ` Kees Cook
2018-09-14 0:03 ` Casey Schaufler
2018-09-14 0:06 ` Kees Cook
2018-09-13 23:51 ` Casey Schaufler
2018-09-13 23:57 ` Kees Cook
2018-09-14 0:08 ` Casey Schaufler
2018-09-14 0:19 ` Kees Cook
2018-09-14 15:57 ` Casey Schaufler
2018-09-14 20:05 ` Kees Cook
2018-09-14 20:47 ` Casey Schaufler [this message]
2018-09-14 18:18 ` James Morris
2018-09-14 18:23 ` John Johansen
2018-09-14 0:03 ` Kees Cook
2018-09-14 2:42 ` Paul Moore
2018-09-11 20:43 ` [PATCH v2 00/10] LSM: Module stacking in support of S.A.R.A and Landlock James Morris
2018-09-12 21:29 ` James Morris
2018-09-16 16:54 ` Salvatore Mesoraca
2018-09-16 17:25 ` Casey Schaufler
2018-09-16 17:45 ` Salvatore Mesoraca
2018-09-18 7:44 ` Mickaël Salaün
2018-09-18 15:23 ` Casey Schaufler
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=b5601e1a-2c29-55f1-63db-01421eeaa6ea@schaufler-ca.com \
--to=casey@schaufler-ca.com \
--cc=adobriyan@gmail.com \
--cc=casey.schaufler@intel.com \
--cc=jmorris@namei.org \
--cc=john.johansen@canonical.com \
--cc=keescook@chromium.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=paul@paul-moore.com \
--cc=penguin-kernel@i-love.sakura.ne.jp \
--cc=sds@tycho.nsa.gov \
--cc=selinux@tycho.nsa.gov \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).