[systemd-devel] [PATCH] SELINUX: add /sys/fs/selinux mount point to put selinuxfs

[Casey Schaufler]

On 5/11/2011 7:58 AM, Eric Paris wrote:
> On Wed, May 11, 2011 at 10:54 AM, John Johansen
> <john.johansen at canonical.com> wrote:
>> On 05/11/2011 04:52 PM, Kay Sievers wrote:
>>> On Wed, May 11, 2011 at 16:43, Greg KH <greg at kroah.com> wrote:
>>>> On Wed, May 11, 2011 at 04:27:59PM +0200, Kay Sievers wrote:
>>>>> On Wed, May 11, 2011 at 15:54, Greg KH <greg at kroah.com> wrote:
>>>>>> On Wed, May 11, 2011 at 01:22:42PM +0200, John Johansen wrote:
>>>>>>> On 05/11/2011 03:59 AM, Greg KH wrote:
>>>>>>>> On Tue, May 10, 2011 at 03:55:24PM -0700, Casey Schaufler wrote:
>>>>>>>>> On 5/10/2011 3:34 PM, Greg KH wrote:
>>>>>>>>>> From: Greg Kroah-Hartman <gregkh at suse.de>
>>>>>>>>>>
>>>>>>>>>> In the interest of keeping userspace from having to create new root
>>>>>>>>>> filesystems all the time, let's follow the lead of the other in-kernel
>>>>>>>>>> filesystems and provide a proper mount point for it in sysfs.
>>>>>>>>>>
>>>>>>>>>> For selinuxfs, this mount point should be in /sys/fs/selinux/
>>>>>>>>> It seems that we might want this to be an LSM interface standard.
>>>>>>>>> Is the call to kobject_create_and_add and associated cleanup all
>>>>>>>>> that's required? I would want Smack to follow the convention as
>>>>>>>>> well.
>>>>>>>> You could always just create a subdir under /sys/security/ if you have
>>>>>>>> your own filesystem, but I don't think that Smack has one, right?
>>>>>>>>
>>>>>>>> Is it going to get one?  If so, we might want to revisit the idea of
>>>>>>>> securityfs if no one is actually using it...
>>>>>>>>
>>>>>>> resending, as this looks to have been lost
>>>>>>>
>>>>>>> AppArmor, IMA, and TOMOYO are using securityfs currently.
>>>>>> Great, then it will not go anywhere.
>>>>> Just to get an idea how all this fits together. How can TPM bios and
>>>>> IMA/AppArmor share this directory? They have their own subdirs in
>>>>> there, or both just use the securityfs infrastructure and not their
>>>>> own filesystem on top?
>>>> Only one security module is allowed to be loaded/active at any one point
>>>> in time, so they can't step on each other.
>>> Right, but what I don't understand is CONFIG_TCG_TPM, which seem to
>>> use securityfs, and is not a LSM. This and AppArmor/IMA can be used at
>>> the same time, can't it? They share securityfs then?
>>>
>> AppArmor, Tomoyo and IMA all create their own subdirectoy under securityfs
>> so this should not be a problem
> I guess the question is, should SELinux try to move to /sys/fs/selinux
> or /sys/security/selinux.  The only minor issue I see with the later
> is that it requires both sysfs and securityfs to be mounted before you
> can mount selinuxfs, whereas the first only requires sysfs.  Stephen,
> Casey, either of you have thoughts on the matter?

I would prefer /sys/security for all LSMs, but if SELinux goes with /sys/fs
Smack will likely follow on the theory that mirroring the current dominant
LSM is more likely to please the masses than doing what the greatest number
of LSMs are doing.