On 12/11/2013 04:36 AM, Serge E. Hallyn wrote: > Quoting Eric Paris (eparis@xxxxxxxxxx): >> On Tue, 2013-12-10 at 10:51 -0600, Serge Hallyn wrote: >>> Quoting Gao feng (gaofeng@xxxxxxxxxxxxxx): >>>> On 12/10/2013 02:26 AM, Serge Hallyn wrote: >>>>> Quoting Gao feng (gaofeng@xxxxxxxxxxxxxx): >>>>>> On 12/07/2013 06:12 AM, Serge E. Hallyn wrote: >>>>>>> Quoting Gao feng (gaofeng@xxxxxxxxxxxxxx): >>>>>>>> Hi >>>>>>>> >>>>>>>> On 10/24/2013 03:31 PM, Gao feng wrote: >>>>>>>>> Here is the v1 patchset: http://lwn.net/Articles/549546/ >>>>>>>>> >>>>>>>>> The main target of this patchset is allowing user in audit >>>>>>>>> namespace to generate the USER_MSG type of audit message, >>>>>>>>> some userspace tools need to generate audit message, or >>>>>>>>> these tools will broken. >>>>>>>>> >>>>>>>> >>>>>>>> I really need this feature, right now,some process such as >>>>>>>> logind are broken in container becase we leak of this feature. >>>>>>> >>>>>>> Your set doesn't address loginuid though right? How exactly do you >>>>>>> expect to do that? If user violates MAC policy and audit msg is >>>>>>> sent to init user ns by mac subsys, you need the loginuid from >>>>>>> init_audit_ns. where will that be stored if you allow updates >>>>>>> of loginuid in auditns? >>>>>>> >>>>>> This patchset doesn't include the loginuid part. >>>>>> >>>>>> the loginuid is stored in task as before. >>>>>> In my opinion, when task creates a new audit namespace, this task's >>>>>> loginuid will be reset to zero, so the children tasks can set their >>>>>> loginuid. Does this change break the MAC? >>>>> >>>>> I think so, yes. In an LSPP selinux environment, if the task >>>>> manages to trigger an selinux deny rule which is audited, then >>>>> the loginuid must make sense on the host. Now presumably it >>>>> will get translated to the mapped host uid, and we can figure >>>>> out the host uid owning it through /etc/subuid. But that adds >>>>> /etc/subuid as a new part of the TCB without any warning <shrug> >>>>> So in that sense, for LSPP, it breaks it. >>>>> >>>> >>>> Looks like my opinion is incorrect. >>>> >>>> In the audit-next tree, Eric added a new audit feature to allow privileged >>>> user to disable AUDIT_LOGINUID_IMMUTABLE. after AUDIT_LOGINUID_IMMUTABLE >>>> is disabled, the privileged user can reset/set the loginuid of task. I >>>> think this way is safe since only privileged user can do the change. >>>> >>>> So I will not change the loginuid part. >>>> >>>> Thanks for your information Serge :) >>> >>> Unfortunately this makes the patchset much less compelling :) The >>> problem I was looking into is that a container running in a user >>> namespace cannot (bc he has ns_capable(CAP_AUDIT_*) but not >>> capable(CAP_AUDIT_*)) set loginuids at all. >>> >>> Which from an LSPP pov is correct; which is why I was hoping you were >>> going to have the audit namespaces be hierarchical, with a task in a >>> level 2 audit ns having two loginuids - one in his own auditns, and >>> one in the initial one. >> >> Right now user namespace + audit is just total crud. We all know >> this... (I'm not sure pid is must better, but I digress) All thoughts >> around loginuid in the kernel right this very moment only make sense in >> the initial user namespace and all permission checks are in the initial >> user namespace as well. >> >> I think I'm a proponent of the hierarchical approach to audit >> namespaces. An audit namespace would hold a reference to the >> pid/user/whatever namespace it was created in/with. Each audit >> namespace should have it's own set of filter rules, etc. Instead of >> just storing 'loginuid' we store 'loginuid+user namespace'. When the > > So long as the kernel stores the kuid_t (which the only sane thing to > do) that is a non-issue. > >> kernel creates a record it should translate the loginuid to the >> namespace of the audit namespace and send the record. > > Yup, that should go without saying. Use kuid_t in kernel and translate > at the kernel-user boundary. > I can implement audit namespace as a hierarchy, give per auditns a level value and a pointer which point to parent auditns. but for the loginuid part, I think we can implement it after we push the audit ns into the upstream. Is this ok? >> It's a pretty major rewrite, but at least it makes sense. Things like >> AVC's might show up in multiple audit logs, but in every log they would >> make sense to the admin of that namespace... >> >> But what the hell do I know... > > Exactly how it would all affect selinux. I'm happy it seems we agree. This idea looks good to me, I will Investigate this. :) Thanks. _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
