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From: Kyle Evans <kevans@freebsd.org>
Date: Sun, 27 Sep 2020 15:09:28 -0500
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Subject: Re: Is it possible to exit the chroot(2) environment?
To: Yuri <yuri@rawbw.com>
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On Sun, Sep 27, 2020 at 3:04 PM Yuri <yuri@rawbw.com> wrote:
>
> On 2020-09-27 12:56, Kyle Evans wrote:
> > kern.chroot_allow_open_directories to some value that isn't 0 or 1.
>
>
> It succeeds with kern.chroot_allow_open_directories=2.
>
>

Ok, so Warner's proposal was correct and we've verified the semantics
work out the same, this is simply a behavioral difference in that
we're a little more strict -- presumably to make it less trivial to
break out of a chroot.

I suspect a default change for the sysctl/behavior is unlikely, your
best bet to move forward is probably to work out if they really need
to have dangling directories open and correct that if at all possible.