Am 06.05.19 um 14:29 schrieb Martin McCormick: > After upgrading 2 older I86 systems to stretch, sudo works on one > and fails on the other but I am writing about both. The problem > was probably on the failing system all along but su still allowed > a su to root under jessie but won't allow it under stretch. > > sudo: pam_open_session: Permission denied > sudo: policy plugin failed session initialization
Ok, this where to start: Have a look at your pam config: - Have there been any changes? Not just recently, but at any time. - What are the modification dates in /etc/pam.d/? - What pam modules are installed? -> dpkg -l | grep pam If I'm not wrong, a systemd module 'libpam-systemd' was introduced with stretch. This has to be present! > > The first thing I did was classic finger-pointing. I > de-installed sudo on the limping system and reinstalled it at > which point the problem persisted. A look at /var/log/auth.log > tells me something but I am not sure what. > > If you look in auth.log, it is peppered with > > May 5 13:11:32 audio3 sudo: PAM no modules loaded for `sudo' service > > This occurs both before and after the upgrade which > succeeds before and fails after. > > The other system which totally survived the upgrade never > shows this message so it seems that the pam service is partly > broken on one and OK on the other. Right now, I can ssh in to > the broken system and do anything but sudo commands. What is the > safest way to rescue the system while still remotely attached via > ssh? > > As I said, the problem may have been here for quite some > time so the upgrade didn't cause it. It just accentuates it > since sudo now complains. > Thanks for all constructive ideas. > > > Martin McCormick WB5AGZ >
