Re: [PATCH 1/3] proc: Stop reporting eip and esp in /proc/PID/stat

[Andy Lutomirski]

On Sat, Oct 1, 2016 at 3:37 AM, Jann Horn <jann@xxxxxxxxx> wrote:
> On Fri, Sep 30, 2016 at 07:01:13PM -0700, Andy Lutomirski wrote:
>> On an unrelated note, can we please lock down all the silly historical
>> *userspace* info leaks in /proc?  Nasty ones include: net, cmdline (at
>> the very least, only argv[0] should be visible if the reader lacks
>> ptrace access).
>>
>> Less nasty ones include: limits, sched, autogroup, comm, wchan,
>> schedstat, cpuset, cgroup, oom_*, sessionid, coredump_filter
>
> If that doesn't break stuff, I'm very much in favor of it.
>
>
>> uid_map, gid_map, etc are just screwed up.  They should be per
>> *namespace* somewhere, and they should require creds on the namespace.
>
> What do you have in mind? Something like
> /proc/namespaces/user:123456/{uid_map,gid_map,setgroups,parent_ns},
> with jumped fake symlinks to the directory and its entries in /proc/$pid/?
>

Something along those lines would be nice.

There's an unfortunate tension between having names for namespaces
(like 123456 in your example) for ease of use and *not* having names
so CRIU can restore them more easily.

>
>> timerslack is totally fscked up -- it allows ugo to write and it
>> checks the wrong creds.  Jann, does your series fix that?
>
> Nope. Never noticed that thing so far, probably because it was only
> added a few months ago. :/ Will add it to my series.



-- 
Andy Lutomirski
AMA Capital Management, LLC