[lxc-devel] Kernel bug? Setuid apps and user namespaces

[Serge Hallyn]

Ok so let's reconsider this.  I was thinking (based on faulty
memory) that the problem was just the pty which get opened
early on during lxc-start, by the init task itself.  But that's
not the case, or at least not the whole story.  Rather, this is a
login spawned by getty in the main console:

300000    2023  1579  0 22:29 ?        00:00:00 /bin/login --       

but ls -l in /proc/2023 shows that everything but net, attr,
and task are owned by root.  Now for the bash spawned by
login, everything under /proc/$pid is owned by 300000,
the mapped uid.

So why is this happening.  It's not due to the task's tty.
That is /dev/lxc/console which is a bind mount of the
host's /dev/pts/7, which is

crw------- 1 301000 300005 136, 7 Oct 28 22:36 7

So is there something we can run from userspace while we are
still pid 1, before executing /sbin/init, to force ourselves
to change to fully "being" 300000 instead of 0?

-serge