Re: [PATCH RFC 00/48] Add namespace support for audit

On 06/07/2013 06:47 AM, Serge Hallyn wrote: > Quoting Serge Hallyn (serge.hallyn(a)ubuntu.com): >> Quoting Gao feng (gaofeng(a)cn.fujitsu.com): >>> On 05/07/2013 10:20 AM, Gao feng wrote: >>>> This patchset try to add namespace support for audit. >>>> >>>> I choose to assign audit to the user namespace. >>>> Right now,there are six kinds of namespaces, such as >>>> net, mount, ipc, pid, uts and user. the first five >>>> namespaces have special usage. the audit isn't suitable to >>>> belong to these five namespaces, so the user namespace >>>> may be the best choice. >>>> >>>> Through I decide to make audit related resources per user >>>> namespace, but audit uses netlink to communicate between kernel >>>> space and user space, and the netlink is a private resource >>>> of per net namespace. So we need the capability to allow the >>>> netlink sockets to communicate with each other in the same user >>>> namespace even they are in different net namespace. [PATCH 2/48] >>>> does this job, it adds a new function "compare" for per netlink >>>> table to compare two sockets. it means the netlink protocols can >>>> has its own compare fuction, For other protocols, two netlink >>>> sockets are different if they belong to the different net namespace. >>>> For audit protocol, two sockets can be the same even they in different >>>> net namespace,we use user namespace not net namespace to make the >>>> decision. >>>> >>>> There is one point that some people may dislike,in [PATCH 1/48], >>>> the kernel side audit netlink socket is created only when we create >>>> the first netns for the userns, and this userns will hold the netns >>>> until we destroy this userns. >>>> >>>> The other patches just make the audit related resources per >>>> user namespace. >>>> >>>> This patchset is sent as an RFC,any comments are welcome. >> >> Hi, >> >> thanks for sending this. I think you need to ping the selinux folks >> for comment though. It appears to me that, after this patchset, the >> kernel with CONFIG_USER_NS=y could not be LSPP-compliant, because >> the selinux-generated audit messages do not always go to init_user_ns. >> >> Additionally, the only type of namespacing selinux wants is where it >> is enforced by policy compiler and installer using typenames - i.e. >> 'container1.user_t' vs 'user_t'. Selinux does not want user namespaces >> to affect selinux enforcement at all. (at least last I knew, several >> years ago at a mini-summit, I believe this was from Stephen Smalley). > > That sort of sounds like I'm distancing myself from that, which I > don't mean to do. I agree with the decison: MAC (selinux, apparmor > and smack) should not be confuddled by user namespaces. (posix caps > are, as always, a bit different). Thanks for your comments! Very useful information, it sounds reasonable. Let's just drop those patches.