pam_userdb.so is missing

[Thomas-Thomas]

[ Impact ]

 * In the process of bootstrapping pam for time_t, libdb-dev was
   deliberately removed in salsa commit 65621d8 to allow libdb-dev to
   undergo time_t transition.
 * The result of that is no pam_userdb.so in libpam-modules
 * The fix takes the form of correcting a build dependency, which
   results in pam_userdb.so being again available.

[ Test Plan ]

 * regression
   * obtain a noble test system - I personally used a noble chroot
   * adjust apt sources and ensure noble-proposed is present
   * install libpam-modules 1.5.3-5ubuntu5.1
   * login to the test machine with appropriate credentials - the
     literal `login` command is useful here
 * userdb functionality
   * start with the same test machine from the regression test
   * install db5.3-util
   * modify /etc/pam.d/login to comment out all `auth` lines, and add
     this instead
```
auth requisite pam_userdb.so db=/etc/dbtest
```
   * create a textfile named `input` that looks like
```
your_username
test_password - different than /etc/shadow
```
   * `db5.3_load -T -f input -t hash /etc/dbtest.db`
   * login to the test machine with your_username and the
     test_password - the literal `login` command is useful here

[ Where problems could occur ]

 * As usual, no SRU has zero risk
 * Any change to pam risks problems in user logins failing, so a
   basic regression test has been provided

[ Other Info ]

 * None at this time

original description follows
---

The file is missing from libpam-modules.
This breaks, for example, existing vsftp configs if it is configured to use pam_userdb.so

Log:

vsftpd: PAM unable to dlopen(pam_userdb.so): /usr/lib/security/pam_userdb.so: cannot open shared object file: No such file or directory
vsftpd: PAM adding faulty module: pam_userdb.so

Apparently there was a change which removed this in the past, and it might be the removal has not been undone, while the package has been released nevertheless.

http://changelogs.ubuntu.com/changelogs/pool/main/p/pam/pam_1.5.3-5ubuntu5/changelog

  * For now remove libdb-dev so that libdb-dev can undergo time_t
    transition. That means this version of pam does not include
    pam_userdb, which makes pam unsuitable for release.

$ lsb_release -rd
No LSB modules are available.
Description: Ubuntu 24.04 LTS
Release: 24.04

$ apt-cache policy libpam-modules
libpam-modules:
  Installed: 1.5.3-5ubuntu5
  Candidate: 1.5.3-5ubuntu5
  Version table:
 *** 1.5.3-5ubuntu5 500
        500 http://de.archive.ubuntu.com/ubuntu noble/main amd64 Packages
        100 /var/lib/dpkg/status

[Timo Aaltonen (tjaalton)]

Hello Thomas-Thomas, or anyone else affected,

Accepted pam into noble-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/pam/1.5.3-5ubuntu5.1 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-noble to verification-done-noble. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-noble. 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.

[Thomas-Thomas (thomas-thomas)]

Version 1.5.3-5ubuntu5.1 of pam indeed fixed my problem. Thank you!

I updated the packages and restarted the vsftpd. It works again now.

[Dan Bungert (dbungert)]

Using a noble schroot, I have confirmed that the fix looks correct.

[Ubuntu SRU Bot (ubuntu-sru-bot)]

All autopkgtests for the newly accepted pam (1.5.3-5ubuntu5.1) for noble have finished running.
The following regressions have been reported in tests triggered by the package:

cron/3.0pl1-184ubuntu2 (s390x)
dovecot/1:2.3.21+dfsg1-2ubuntu5 (s390x)
inetutils/2:2.5-3ubuntu4 (s390x)
libreswan/4.14-1ubuntu2 (s390x)
lxc/1:5.0.3-2ubuntu7 (s390x)
openssh/unknown (armhf, s390x)
samba/2:4.19.5+dfsg-4ubuntu9 (s390x)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-migration/noble/update_excuses.html#pam

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!