I assume you mean the inetd-style [email protected], not the regular sshd.service? (Or does your distribution patch systemd-style socket activation into sshd?)
There is usually no dependency on a shell, unless the .service unit explicitly calls /bin/sh (note that the inetd-style socket activation uses a different .service). Forkstat or extrace can reveal what is being exec'd when the connection is made. On Thu, Aug 1, 2024, 15:40 Mark Corbin <[email protected]> wrote: > Hello > > I was wondering whether anybody has any experience of running the sshd > service successfully on a system with a 'non-bash' shell? > > We're using systemd 250.5 and openssh 8.9p1. Both ssh and scp work as > expected with '/bin/sh -> bash.bash' on the target, but with '/bin/sh -> > busybox.nosuid' (ash shell) the connections fail. > > The sshd logs on the target show: > Jul 31 15:24:56 hc sshd[17826]: Connection from UNKNOWN port 65535 on > 192.168.12.246 port 65535 > Jul 31 15:24:56 hc sshd[17826]: debug1: kex_exchange_identification: > write: Broken pipe > Jul 31 15:24:56 hc sshd[17826]: banner exchange: Connection from UNKNOWN > port 65535: Broken pipe > > Some extra debug messages that I've added to both systemd and sshd show > that the incoming socket gets closed somewhere between the handover from > the systemd socket service to the systemd sshd service. This results in > sshd being unable to get any peer details. The call to getpeername in > service_spawn fails with ENOTCONN. > > I can't see anything obvious in either the systemd source that suggests a > dependency on bash. > > Any ideas gratefully appreciated. > > Regards > > Mark > > -- > > *Mark Corbin * > Senior Software Engineer | lunarenergy.com > <https://www.lunarenergy.com> | LinkedIn > <https://www.linkedin.com/company/lunarenergyinc/> | Instagram > <https://www.instagram.com/lunarenergyinc/> > [image: Lunar Energy Logo] > > C2:Restricted unless otherwise stated. > > Lunar Energy Limited is a company registered in England and > Wales, authorised and regulated by the Financial Conduct Authority under > reference number 767876. Company registration number: 05631091. Registered > office: 55 Baker Street, London, England, W1U 7EU > <https://www.google.com/maps/search/55+Baker+Street,+London,+England,+W1U+7EU?entry=gmail&source=g> >
