[8.0p1] After the remote ssh command execution, the session does not terminate until an active disconnect

[Damien Miller]

On Tue, 20 Aug 2019, Jakub Jelen wrote:

> On Tue, 2019-08-20 at 16:00 +0900, Hong Cho wrote:
> > Thank you for the reply.
> > 
> > I changed the remote command to a generic example because in our
> > case, we
> > are using an internal binary that I didn't want to make public. I
> > thought
> > it wouldn't matter, but apparently, it does. I am sorry I can't share
> > more
> > about this tool.
> > 
> > BTW, our environment is based on FreeBSD, not on Linux. In our case,
> > because "isatty" is set to 0, it never closes.
> 
> It never closes, because the `tail -f` never exists and never closes
> the stdout and stderr that are connected to ssh channels.
> 
> Yes, this is a difference from the previous openssh versions, but I
> think this is a correct behavior. Previously, the ssh ran the command
> in background and closed its IO.

AFAIK that's not the case - the behaviour change only affects programs
that output to stderr.

OpenSSH 7.2 doesn't exit "tail -f &" either, because it doesn't
write anything to stderr.

-d