Bug#1093274: Unattended upgrades fails to upgrade dnsmasq due to configuration file changes

[Tianyu Chen]

Package: dnsmasq
Version: 2.90-4~deb12u1
Severity: serious
X-Debbugs-Cc: ***@gmail.com, Lee Garrett <***@rocketjump.eu>, Simon Kelley <***@thekelleys.org.uk>, Sven Geuer <***@g-e-u-e-r.de>

Hi,

When SSHing to my server, I've received the following message:

1 updates could not be installed automatically. For more details,
see /var/log/unattended-upgrades/unattended-upgrades.log

The relevant log entries are:

2025-01-17 06:54:23,555 INFO Starting unattended upgrades script
2025-01-17 06:54:23,557 INFO Allowed origins are: origin=Debian,codename=bookworm,label=Debian, origin=Debian,codename=bookworm,label=Debian-Security, origin=Debian,codename=bookworm-security,label=Debian-Security
2025-01-17 06:54:23,557 INFO Initial blacklist:
2025-01-17 06:54:23,557 INFO Initial whitelist (not strict):
2025-01-17 06:54:26,110 WARNING Package dnsmasq has conffile prompt and needs to be upgraded manually
2025-01-17 06:54:26,730 INFO package dnsmasq not upgraded
2025-01-17 06:54:27,035 INFO No packages found that can be upgraded unattended and no pending auto-removals
2025-01-17 06:54:27,050 INFO Package dnsmasq is blacklisted.

When attempting to upgrade dnsmasq manually, I encounter a configuration file prompt:

Preparing to unpack .../dnsmasq_2.90-4~deb12u1_all.deb ...
Unpacking dnsmasq (2.90-4~deb12u1) over (2.89-1) ...
Setting up dnsmasq (2.90-4~deb12u1) ...
Installing new version of config file /etc/default/dnsmasq ...

Configuration file '/etc/dnsmasq.conf'
==> Modified (by you or by a script) since installation.
==> Package distributor has shipped an updated version.
What would you like to do about it ? Your options are:
Y or I : install the package maintainer's version
N or O : keep your currently-installed version
D : show the differences between the versions
Z : start a shell to examine the situation
The default action is to keep your current version.
*** dnsmasq.conf (Y/I/N/O/D/Z) [default=N] ? D

This behavior is unexpected because the dnsmasq.conf change caused the
package cannot be upgraded automatically. So I've raised the severity to
serious.

Thanks for your contribution!

Best regards,
Tianyu Chen

-- System Information:
Debian Release: 12.9
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 6.1.0-23-amd64 (SMP w/1 CPU thread; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages dnsmasq depends on:
ii dnsmasq-base [dnsmasq-base] 2.90-4~deb12u1
ii init-system-helpers 1.65.2
ii netbase 6.4
ii runit-helper 2.15.2

dnsmasq recommends no packages.

Versions of packages dnsmasq suggests:
ii resolvconf 1.91+nmu1

-- Configuration Files:
/etc/dnsmasq.conf changed [not included]

[Tianyu Chen]

this is indeed caused by the one character typo fix in the config file, which
prompts for the conffile change you see here. While this is unfortunate,
reverting the change in a new update would just trigger the same issue again. As
such, there is nothing to act on here.

Agree. We can do nothing now.

I failed to detect the fix you mentioned. Can you give me a hint?
Also note, I could not reproduce any issue upgrading from an unchanged
2.89-1 installation [1].

I actually deleted all the default content in /etc/dnsmasq.conf and manually
wrote a completely new configuration file. Therefore, during the upgrade,
any single character modification in dnsmasq.conf required manual intervention.

Best regards,
Tianyu Chen