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

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/?

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.