Re: [RFC Part1 PATCH 00/20 v2] Add namespace support for audit

Gao feng
2013-11-05T07:51:55Z

Ping...

On 10/31/2013 11:52 AM, Gao feng wrote:
> Hi Eric Paris,
>
> Can you give me some comments?
>
> You think the tying audit namespace to user namespace is a bad idea,
> so this patchset doesn't assign auditns to userns and introduce an
> new audit netlink type to help to create audit namespace.
>
> and this patchset also introduces an new proc interface to make
> sure container can't influence the whole system.
>
> and the audit rules are not namespace aware, all of audit namespaces
> should comply with the rules. in next step, if we find it's need to
> make audit rules per audit namespace, then it's the time to do that
> job.
>
> This patchset also makes all of net namespaces have ability to send/
> receive audit netlink message.
>
> I may miss some points, if you find there are some shortage or loophole,
> please let me know.
>
> Thanks!
>
> 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.
>>
>> And the login process in container may want to setup
>> /proc/<pid>/loginuid, right now this value is unalterable
>> once it being set. this will also broke the login problem
>> in container. After this patchset, we can reset this loginuid
>> to zero if task is running in a new audit namespace.
>>
>> Same with v1 patchset, in this patchset, only the privileged
>> user in init_audit_ns and init_user_ns has rights to
>> add/del audit rules. and these rules are gloabl. all
>> audit namespace will comply with the rules.
>>
>> Compared with v1, v2 patch has some big changes.
>> 1, the audit namespace is not assigned to user namespace.
>> since there is no available bit of flags for clone, we
>> create audit namespace through netlink, patch[18/20]
>> introduces a new audit netlink type AUDIT_CREATE_NS.
>> the privileged user in userns has rights to create a
>> audit namespace, it means the unprivileged user can
>> create auditns through create userns first. In order
>> to prevent them from doing harm to host, the default
>> audit_backlog_limit of un-init-audit-ns is zero(means
>> audit is unavailable in audit namespace). and it can't
>> be changed in auditns through netlink.
>>
>> 2, introduce /proc/<pid>/audit_log_limit
>> this interface is used to setup log_limit of audit
>> namespace. we need this interface to make audit
>> available in un-init-audit-ns. Only the privileged user
>> has right to set this value, it means only the root user
>> of host can change it.
>>
>> 3, make audit namespace don't depend on net namespace.
>> patch[1/20] add a compare function audit_compare for
>> audit netlink, it always return true, it means the
>> netlink subsystem will find out the netlink socket
>> only through portid and netlink type. So we needn't
>> to create kernel side audit netlink socket for per
>> net namespace, all userspace audit netlink socket
>> can find out the audit_sock, and audit_sock can
>> communicate with them through the proper portid.
>> it's just like the behavior we don't have net
>> namespace before.
>>
>>
>> This patchset still need some work, such as allow changing
>> audit_enabled in audit namespace, auditd wants this feature.
>>
>> I send this patchset now in order to get more comments, so
>> I can keep on improving namespace support for audit.
>>
>> Gao feng (20):
>> Audit: make audit netlink socket net namespace unaware
>> audit: introduce configure option CONFIG_AUDIT_NS
>> audit: make audit_skb_queue per audit namespace
>> audit: make audit_skb_hold_queue per audit namespace
>> audit: make audit_pid per audit namespace
>> audit: make kauditd_task per audit namespace
>> aduit: make audit_nlk_portid per audit namespace
>> audit: make kaudit_wait queue per audit namespace
>> audit: make audit_backlog_wait per audit namespace
>> audit: allow un-init audit ns to change pid and portid only
>> audit: use proper audit namespace in audit_receive_msg
>> audit: use proper audit_namespace in kauditd_thread
>> audit: introduce new audit logging interface for audit namespace
>> audit: pass proper audit namespace to audit_log_common_recv_msg
>> audit: Log audit pid config change in audit namespace
>> audit: allow GET,SET,USER MSG operations in audit namespace
>> nsproxy: don't make create_new_namespaces static
>> audit: add new message type AUDIT_CREATE_NS
>> audit: make audit_backlog_limit per audit namespace
>> audit: introduce /proc/<pid>/audit_backlog_limit
>>
>> fs/proc/base.c | 53 ++++++
>> include/linux/audit.h | 26 ++-
>> include/linux/audit_namespace.h | 92 ++++++++++
>> include/linux/nsproxy.h | 15 +-
>> include/uapi/linux/audit.h | 1 +
>> init/Kconfig | 10 ++
>> kernel/Makefile | 2 +-
>> kernel/audit.c | 364 +++++++++++++++++++++++++---------------
>> kernel/audit.h | 5 +-
>> kernel/audit_namespace.c | 123 ++++++++++++++
>> kernel/auditsc.c | 6 +-
>> kernel/nsproxy.c | 18 +-
>> 12 files changed, 561 insertions(+), 154 deletions(-)
>> create mode 100644 include/linux/audit_namespace.h
>> create mode 100644 kernel/audit_namespace.c
>>
>
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