[SRU] kernel package names ending with version without flavor are not matched by generated patterns

[Balint Reczey]

[Impact]

 * Most of the unused kernel packages are automatically removed by u-u, but kernel packages not including the flavor in the name are not removed taking up significant space after some time:
 $ sudo apt autoremove
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  linux-gcp-headers-4.15.0-1018 linux-gcp-headers-4.15.0-1019 linux-gcp-headers-4.15.0-1021 linux-gcp-headers-4.15.0-1024 linux-gcp-headers-4.15.0-1025 linux-gcp-headers-4.15.0-1026 linux-gcp-headers-4.15.0-1027
  linux-gcp-headers-4.15.0-1028 linux-gcp-headers-4.15.0-1029 linux-gcp-headers-4.15.0-1030 linux-gcp-headers-4.15.0-1032 linux-gcp-headers-4.15.0-1033 linux-gcp-headers-4.15.0-1034 linux-gcp-headers-4.15.0-1036
  linux-gcp-headers-4.15.0-1037 linux-gcp-headers-4.15.0-1042 nplan
0 upgraded, 0 newly installed, 17 to remove and 16 not upgraded.
After this operation, 1234 MB disk space will be freed.
Do you want to continue? [Y/n]

[Test Case]

 * A new test case is added to autopkgtest (test/autopkgtest_kernel_patterns.py) to verify that all kernel-related packages are covered having the same version of the running kernel.

 * Install linux-gcp-headers-4.15.0-1042 and make it autoremovable
 * Run unattended-upgrades
 * Observe linux-gcp-headers-4.15.0-1042 being autoremoved with fixed u-u versions.

[Regression Potential]

 * With the file name patterns changing u-u may select packages with names matching the patterns but not being versioned kernel packages. In case those packages are autoremovable they are removed by u-u.
To avoid this problem the fix for LP: #1848706 ensures that only linux-related packages are autoremoved in the kernel autoremoval phase.

[Original Bug Text]

Apt ships VersionedKernelPackages regex patterns in /etc/apt/apt.conf.d/01autoremove from which /etc/kernel/postinst.d/apt-auto-removal generates kernel package name patterns by appending the running kernel version including the flavor like linux-.*-4.15.0-1010-kvm but those generated patterns don't cover versioned kernel package names including the version without the flavor, such as linux-kvm-tools-4.15.0-1012.

Unattended-upgrades generates the patterns in a similar way and also don't cover linux-kvm-tools-4.15.0-1012 and similar packages.

[Balint Reczey (rbalint)]

U-u fix:
https://github.com/mvo5/unattended-upgrades/pull/199

[Launchpad Janitor (janitor)]

This bug was fixed in the package unattended-upgrades - 1.13

---------------
unattended-upgrades (1.13) unstable; urgency=medium

  [ Alban VIDAL ]
  * Update french translation.
    Signed-off-by: Alban VIDAL <email address hidden>

  [ Balint Reczey ]
  * Don't crash collecting transitive dependencies when package has no
    candidate (LP: #1825886)
  * Use mark_install_adjusted() in rewind_cache()
    The original cache had packages marked with adjustments thus rewinding
    should also do adjustments to reach the same state. Not using
    mark_install_adjusted() also crashes when apt raises error on held
    packages. (LP: #1826157)
  * test_rewind: Update test to check if adjustend rewinding took place
  * Only allow removals in valid autoremoval sets
  * Fix one more log location in the man page (Closes: #928601)
  * Factor out kernel regexp generation to functions
  * Packages including kernel version without flavor in their name may be
    kernel packages. Also add autopkgtest for checking if the generated
    patterns cover the currently running kernel. (LP: #1828200)
  * Skip upgrade-all-security test when there are no updates to test with.
    Shortly after a release there may not be security updates against the
    packages used in the chroot used for the test.
  * Test with latest stable in upgrade-all-security on testing
  * Fix testing Debian's updates in upgrade-all-security
  * Store list of kept packages and report the number of them in motd
    (LP: #1823070)
  * Mention APT's apt-daily-upgrade.service in the man page
  * 50unattended-upgrades.md5sum add MD5 of current files
  * PEP8: Fix breaking line after binary operator
  * debian/tests/control: Fix Depends: of upgrade-between-snapshots
  * debian/tests/control: Allow stderr in kernel-patterns

  [ Gordon Lack ]
  * Replace boolean Unattended-Upgrade::MailOnlyOnError2 mail reporting setting
    with multi-valued (string) Unattended-Upgrade::MailReport.

  [ Jaime Hablutzel ]
  * Error message improved on very improbable condition

  [ Clint Armstrong ]
  * Fix showing multi-line strings on Plymouth.
    When unattended-upgrades sends it's status to plymouth it sends a
    multi-line string which causes plymouth to display overlapping text,
    because plymouth only scrolls one line when the message is sent.
    (LP: 1826406)

 -- Balint Reczey <email address hidden> Mon, 08 Jul 2019 11:08:30 +0200