WARNING: openntpd upgrade breaks openssh on next restart

[Vesa Kaihlavirta-2]

Hey,

I made a screwup on the openntpd package which nastily reveals a
weakness in openssh and filesystems. I moved away from using
/var/empty/ as a privsep directory, and removed the directory from the
package. But since it's empty, it got removed from the system as well
in the upgrade.

So if you're using openntpd and openssh, BE EXTRA CAREFUL with your
next upgrade. openssh does not start if /var/empty/ is not there.

Quick fix: after doing pacman -Suy, do mkdir /var/empty as root.

Longer fix: openssh, or perhaps the filesystems package should create
/var/empty/ and put a hidden file in it so idiots like me won't cause
accidents in the future.

--vk

[Roman Kyrylych]

On Mon, Nov 2, 2009 at 09:48, Vesa Kaihlavirta <vpkaihla@...> wrote:

> Hey,
>
> I made a screwup on the openntpd package which nastily reveals a
> weakness in openssh and filesystems. I moved away from using
> /var/empty/ as a privsep directory, and removed the directory from the
> package. But since it's empty, it got removed from the system as well
> in the upgrade.
>
> So if you're using openntpd and openssh, BE EXTRA CAREFUL with your
> next upgrade. openssh does not start if /var/empty/ is not there.
>
> Quick fix: after doing pacman -Suy, do mkdir /var/empty as root.
>
> Longer fix: openssh, or perhaps the filesystems package should create
> /var/empty/ and put a hidden file in it so idiots like me won't cause
> accidents in the future.

Correction: the latest openssh package (3.5p1-2)
works around missing /var/empty by creating it in rc.d daemon.


P.S.:
I'm not sure putting a hidden file in /var/empty is not against it's purpose
(which I suppose is "to be empty").
We are discussing ways to eliminate the problem completely.

--
Roman Kyrylych (Роман Кирилич)

[Vesa Kaihlavirta-2]

On Mon, Nov 2, 2009 at 10:25 AM, Roman Kyrylych
<roman.kyrylych@...> wrote:

> Correction: the latest openssh package (3.5p1-2)
> works around missing /var/empty by creating it in rc.d daemon.

Ah yes, good.

I did notice the thread elsewhere, just thought I'll emphasize a bit
to lower the number of broken headless opensshs out there...


> P.S.:
> I'm not sure putting a hidden file in /var/empty is not against it's purpose
> (which I suppose is "to be empty").

Indeed.

--vk