sudo -p '' displays a password prompt which it shouldn't

[David Partridge]

I have small script that invokes another shell script as root thus:

#!/bin/bash
echo "mypass" | sudo -p '' -S /usr/StorMan/StorMan.sh

when running in 16.04 LTS this didn't display a password prompt which I understand to be correct behaviour. Since upgrading to 18.04.1 LTS the output looks like:

amonra@Charon:~$ ./storman
[sudo] password for amonra:

which as far as I can determine is not correct.

Thanks
Dave

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: sudo 1.8.21p2-3ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-38.41-generic 4.15.18
Uname: Linux 4.15.0-38-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.4
Architecture: amd64
CurrentDesktop: LXDE
Date: Thu Oct 25 03:07:27 2018
InstallationDate: Installed on 2016-03-28 (940 days ago)
InstallationMedia: Ubuntu-Server 14.04.4 LTS "Trusty Tahr" - Release amd64 (20160217.1)
SourcePackage: sudo
UpgradeStatus: Upgraded to bionic on 2018-10-22 (2 days ago)
VisudoCheck:
 /etc/sudoers: parsed OK
 /etc/sudoers.d/README: parsed OK
modified.conffile..etc.sudoers: [inaccessible: [Errno 13] Permission denied: '/etc/sudoers']
modified.conffile..etc.sudoers.d.README: [inaccessible: [Errno 13] Permission denied: '/etc/sudoers.d/README']

[Karl Stenerud (kstenerud)]

Confirmed incorrect behavior in bionic. xenial and cosmic behave correctly.

[Karl Stenerud (kstenerud)]

I've unfortunately hit a wall investigating this :(

sudo should only override the prompt if passprompt_override is set in sudoers, or the env variable SUDO_PROMPT is set, and neither is set in bionic. Furthermore, it's not an issue with the binary, as I've tried taking the bionic sudo and putting it in a cosmic machine, and it works perfectly, honoring -p '' like the cosmic version does. That leaves the environment somehow, but I've run out of leads.

It does work properly in xenial and in cosmic, and the prompt seems to just be cosmetic anyway, so I'm marking this wontfix.

[David Partridge (perdrix)]

There must be something in the code that is causing this. I confirm that neither the EV SUDO_PROMPT, nor passprompt_override in /etc/sudoers are set.

While I agree that it's purely cosmetic, it would be nice to have it fixed (pretty please).

Cheers
Dave

[David Partridge (perdrix)]

This was fixed in sudo 1.8.22 by the following commit:
https://www.sudo.ws/repos/sudo/rev/93cc4f4761f3

[David Partridge (perdrix)]

I installed sudo 1.8.23-2 from the cosmic repository and can confirm that if fixes the problem

Dave

[Robie Basak (racb)]

Let's leave this open since the bug appears valid and somebody else might be able to volunteer the fix.

[David Partridge (perdrix)]

Robie, it's already fixed see my earlier posts to this thread.

Dave

[Robie Basak (racb)]

Yes, but the fix will need to be backported and tested in Bionic separately, if you want Bionic fixed. The final backported patch needs to be a "debdiff" or contain the equivalent information, including the changelog entry, etc. See https://wiki.ubuntu.com/StableReleaseUpdates#Procedure for details.