Re: [PATCH] security: selinux: allow per-file labeling for cgroupfs

[Paul Moore]

On Fri, Mar 10, 2017 at 3:21 PM, Paul Moore <paul@xxxxxxxxxxxxxx> wrote:
> On Fri, Mar 10, 2017 at 3:17 PM, Stephen Smalley <sds@xxxxxxxxxxxxx> wrote:
>> On Fri, 2017-03-10 at 15:01 -0500, Paul Moore wrote:
>>> On Thu, Feb 9, 2017 at 10:58 AM, Antonio Murdaca <amurdaca@xxxxxxxxxx
>>> > wrote:
>>> >
>>> > This patch allows genfscon per-file labeling for cgroupfs. For
>>> > instance,
>>> > this allows to label the "release_agent" file within each
>>> > cgroup mount and limit writes to it.
>>> >
>>> > Signed-off-by: Antonio Murdaca <runcom@xxxxxxxxxx>
>>> > ---
>>> >  security/selinux/hooks.c | 2 ++
>>> >  1 file changed, 2 insertions(+)
>>>
>>> Now that the merge window is behind us, let's get this merged, but
>>> could you update it to use the selinux_policycap_cgroupseclabel
>>> policy
>>> capability?  See 2651225b5ebcdde ("selinux: wrap cgroup seclabel
>>> support with its own policy capability") for more information.
>>
>> I don't think that is necessary.  This change unlike the other one
>> should not yield any difference in behavior with existing policy; it
>> just allows one to specify fine-grained labeling for cgroup nodes in
>> future policy.  It doesn't affect any userspace interface.
>
> Yes, I thought about that, and if the policy capability was already
> present in a released kernel then I wouldn't worry about it much, but
> since the policy capability still only lives in the v4.11-rcX kernels
> I'd prefer to see this code wrapped with the policy capability ...
> even if all it really does is give me that warm fuzzy feeling.

FWIW, I just decided I didn't care that much about the policy
capability restriction for this patch and went ahead and merged it
into selinux/next.

-- 
paul moore
www.paul-moore.com