Bug#903603: ssh upgrade breaks in some openvz container

[Colin Watson <cjwatson@debian.org>]

On Mon, Jul 30, 2018 at 04:50:42PM -0400, Joey Hess wrote:
> I don't get the impression the hosting provider is going to be of any help;
> they're of the bagain basement variety and are struggling with the concept
> that a newer kernel is also needed for eg, running systemd.

Oh dear.

> Based on uname output of "2.6.32-openvz-042stab127.2-amd64 #1 SMP Thu Jan 4 16:43:57 MSK 2018"
> the kernel binary comes directly from openvz.org so you seem to have
> the matching source.
> 
> Interestingly, running as root, strace bash -c 'ulimit -Sn 0 -Hn 0' results in:
> 
> setrlimit(RLIMIT_NOFILE, {rlim_cur=0, rlim_max=0}) = 0
> 
> So that kernel doesn't generally fail when called with those parameters.
> It seems like something else that ssh does may be leading to the EINVAL?

Hmm.  That's kind of startling, since it hasn't really done that much
else by that point (at least not in the sandbox child).  Can you start
up sshd (maybe on a spare port) under strace -f and see if that reveals
any oddities?

Failing that, is there any way I could get root access to an environment
where it's possible to reproduce the bug so that I can experiment?  My
efforts at zen-debugging this aren't really getting anywhere fast.

Thanks,

-- 
Colin Watson                                       [cjwatson@debian.org]