Hello Victor, or anyone else affected, Accepted shadow into hirsute-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/shadow/1:4.8.1-1ubuntu8.1 in a few hours, and then in the -proposed repository.
Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users. If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed- hirsute to verification-done-hirsute. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-hirsute. In either case, without details of your testing we will not be able to proceed. Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping! N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days. ** Changed in: shadow (Ubuntu Hirsute) Status: In Progress => Fix Committed ** Tags added: verification-needed verification-needed-hirsute -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to shadow in Ubuntu. https://bugs.launchpad.net/bugs/1927078 Title: Don't allow useradd to use fully numeric names Status in shadow package in Ubuntu: Fix Released Status in shadow source package in Focal: In Progress Status in shadow source package in Groovy: Won't Fix Status in shadow source package in Hirsute: Fix Committed Status in shadow source package in Impish: Fix Released Bug description: [Impact] * If a fully numeric username is created, it will cause problems with systemd. One example is that the user with this type of name can log in, but loginctl will not create a session for them. * This can also cause users to be unable to log in to a gdm environment [Test Case] * `useradd 123` (this command should succeed) * `userdel 123` to clean up the user that was just added * Install `shadow` from -proposed * `useradd 123` should now fail [Regression Potential] * If there were a logic error in the fix, it is possible that valid usernames would now be disallowed. * Many test cases have been added to ensure this is not the case, and --badnames would still provide a work-around * [racb] Users may have scripts that are currently using numeric usernames and these scripts will break as a consequence of this deliberate change in stable Ubuntu releases. However, based on the discussion in the bug, we think this is preferable to leaving such users with unstable behaviour such as systemd's behaviour described. [Original Description] Fully numeric names support in Ubuntu is inconsistent in Focal onwards because systemd does not like them[1] but are still allowed by default by useradd, leaving the session behavior in hands of the running applications. Two examples: 1. After creating a user named "0", the user can log in via ssh or console but loginctl won't create a session for it: root@focal:/home/ubuntu# useradd -m 0 root@focal:/home/ubuntu# id 0 uid=1005(0) gid=1005(0) groups=1005(0) .. 0@192.168.122.6's password: Welcome to Ubuntu 20.04.2 LTS (GNU/Linux 5.8.0-48-generic x86_64) Last login: Thu Apr 8 16:17:06 2021 from 192.168.122.1 $ loginctl No sessions. $ w 16:20:09 up 4 min, 1 user, load average: 0.03, 0.14, 0.08 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT 0 pts/0 192.168.122.1 16:17 0.00s 0.00s 0.00s w And pam-systemd shows the following message: Apr 08 16:17:06 focal sshd[1584]: pam_unix(sshd:session): session opened for user 0 by (uid=0) Apr 08 16:17:06 focal sshd[1584]: pam_systemd(sshd:session): pam-systemd initializing Apr 08 16:17:06 focal sshd[1584]: pam_systemd(sshd:session): Failed to get user record: Invalid argument 2. With that same username, every successful authentication in gdm will loop back to gdm again instead of starting gnome, making the user unable to login. Making useradd fail (unless --badnames is set) when a fully numeric name is used will make the default OS behavior consistent. [Other info] - Upstream does not support fully numeric usernames - useradd has a --badnames parameter that would still allow the use of these type of names To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/shadow/+bug/1927078/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
