Messages in this thread | | | Date | Wed, 04 Sep 2013 17:04:00 +0200 | From | Jan Kaluža <> | Subject | Re: [PATCH v3 0/3] Send audit/procinfo/cgroup data in socket-level control message |
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On 09/04/2013 04:58 PM, Richard Guy Briggs wrote: > On Wed, Sep 04, 2013 at 12:42:26AM -0700, Eric W. Biederman wrote: >> Jan Kaluza <jkaluza@redhat.com> writes: >>> Hi, >>> >>> this patchset against net-next (applies also to linux-next) adds 3 new types >>> of "Socket"-level control message (SCM_AUDIT, SCM_PROCINFO and SCM_CGROUP). >>> >>> Server-like processes in many cases need credentials and other >>> metadata of the peer, to decide if the calling process is allowed to >>> request a specific action, or the server just wants to log away this >>> type of information for auditing tasks. >>> >>> The current practice to retrieve such process metadata is to look that >>> information up in procfs with the $PID received over SCM_CREDENTIALS. >>> This is sufficient for long-running tasks, but introduces a race which >>> cannot be worked around for short-living processes; the calling >>> process and all the information in /proc/$PID/ is gone before the >>> receiver of the socket message can look it up. >> >>> Changes introduced in this patchset can also increase performance >>> of such server-like processes, because current way of opening and >>> parsing /proc/$PID/* files is much more expensive than receiving these >>> metadata using SCM. >> >> Can I just say ick, blech, barf, gag. > > /me hands ebiederman an air sickness bag. > >> You don't require this information to be passed. You are asking people >> to suport a lot of new code for the forseeable future. The only advantage >> appears to be for short lived racy processes that don't even bother to >> make certain their message was acknowleged before exiting. >> >> You sent this during the merge window which is the time for code >> integration and testing not new code. > > This is an RFC. How is this important? > >> By my count you have overflowed cb in struct sk_buff and are stomping on >> _skb_refdest. > > For patch1/3 I count 56/48, then for patch3 I get 48/48. Jan, you might > do the conversion to a pointer in patch1/3 to avoid bisect breakage.
Yes, this is valid point. I will do the conversion in patch1. Thanks all for reviewing and pointing that out.
Jan Kaluza
>> If you are going to go crazy and pass things is there a reason you do >> not add a patch to pass the bsd SCM_CREDS? That information seems more >> relevant in a security context and for making security decisions than >> about half the information you are passing. >> >> Eric > > - RGB > > -- > Richard Guy Briggs <rbriggs@redhat.com> > Senior Software Engineer > Kernel Security > AMER ENG Base Operating Systems > Remote, Ottawa, Canada > Voice: +1.647.777.2635 > Internal: (81) 32635 > Alt: +1.613.693.0684x3545 >
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