[FFe] apparmor 3 upstream release

[Jamie Strandboge]

As per the draft upstream release notes[1]:

AppArmor 3.0 is a major new release of the AppArmor user space that makes
an important change to policy development and support. Its focus is
transitioning policy to the new features ABI and as such other new features
have been limited.

Apprmor 3.0 is a bridge release between older AppArmor 2.x policy and the
newer AppArmor 3 style policy which requires the declaration of a features
abi. As such AppArmor 3.0 will be a short lived release, and will not
receive long term support. The following AppArmor 3.1 feature release is
planned to be a regular release, please take this into account when
including AppArmor 3.0 into a distro release.

As such, Ubuntu 20.10 provides a great opportunity to introduce AppArmor3
to Ubuntu and provide these new capabilities to users and system
administrators. The short support lifespan of Ubuntu 20.10 ensures that
there is alignment with the limited support lifetime of AppArmor 3.0 from
upstream, whilst giving good exposure and opportunity to test and exercise
the new features in AppArmor 3.x on the road to Ubuntu 22.04. A highlight
of new features provided by AppArmor 3.0 include:

- Policy now must declare the feature abi it was developed for if it is to
  use any new features. This ensures that old policy will not become
  incompatible with new kernels that support additional AppArmor features.
- The use of profile names that are based on pathnames are deprecated.
- Support for new kernel features (requires appropriate features abi
  tagging in policy)
  - upstream v8 network socket rules
  - xattr attachment conditionals
  - capabilities PERFMON and BPF
- Improved compiler warnings and semantic checks
- aa-status rewritten in C (previously was python) with additional features
  - supports use in systems/images where python is not available
  - supports kill, unconfined and mixed profile modes
- Rewritten aa-notify (previously was perl, now python3)
  - shared backend with other python tools
  - support use of aa.CONFDIR instead of hard coded /etc/apparmor
  - improved message layout
- Improved support for kernels that support LSM stacking
- New utility aa-features-abi to extract and work with kernel abi features
- New utility aa-load to load binary policy without calling the
  apparmor_parser
- Support for profile modes
  - enforce (default when no mode flag is supplied)
  - kill (experimental)
  - unconfined (experimental)

The use of the new AppArmor profile feature ABI includes a default
configuration (for the Ubuntu packaged version of AppArmor proposed in this
FFE) for the AppArmor features within the 5.4 Linux kernel - this ensures
that all profiles provided in AppArmor3 for groovy will conform to this
feature set and that upgrades to the kernel version (say to 5.8) that may
include newer AppArmor confinement features will not result in additional
policy denials as a result (since say the existing profile did not specify
a rule for a new AppArmor feature which is now supported by the upgraded
kernel). This ensures that there will be no regressions in application
behaviour as a result of AppArmor kernel feature upgrades.

TESTING

This has been extensively tested by the security team - this includes
following the documented Ubuntu merges test plan[2] for AppArmor and the
extensive QA Regression Tests[3] for AppArmor as well. This ensures that the
various applications that make heavy use of AppArmor (LXD, docker, lxc,
dbus, libvirt, snapd etc) have all been exercised and no regressions have
been observed. All tests have passed and demonstrated both apparmor and the
various applications that use it to be working as expected.

BUILD LOGS

This is currently uploaded to groovy-proposed, build logs can be found on
Launchpad at:
https://launchpad.net/ubuntu/+source/apparmor/3.0.0~beta1-0ubuntu1

INSTALL LOG

See attached (https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/1895060/+attachment/5411197/+files/groovy-proposed-apparmor-install.log) for a log showing install of the packages from groovy-proposed

[1] https://gitlab.com/apparmor/apparmor/-/wikis/Release_Notes_3.0
[2] https://wiki.ubuntu.com/Process/Merges/TestPlans/AppArmor
[3] https://git.launchpad.net/qa-regression-testing/tree/scripts/test-apparmor.py

[Alex Murray (alexmurray)]

As per the draft upstream release notes:

AppArmor 3.0 is a major new release of the AppArmor user space that makes
an important change to policy development and support. Its focus is
transitioning policy to the new features ABI and as such other new features
have been limited.

Apprmor 3.0 is a bridge release between older AppArmor 2.x policy and the
newer AppArmor 3 style policy which requires the declaration of a features
abi. As such AppArmor 3.0 will be a short lived release, and will not
receive long term support. The following AppArmor 3.1 feature release is
planned to be a regular release, please take this into account when
including AppArmor 3.0 into a distro release.

As such, Ubuntu 20.10 provides a great opportunity to introduce AppArmor3
to Ubuntu and provide these new capabilities to users and system
administrators. The short support lifespan of Ubuntu 20.10 ensures that
there is alignment with the limited support lifetime of AppArmor 3.0 from
upstream, whilst giving good exposure and opportunity to test and exercise
the new features in AppArmor 3.x on the road to Ubuntu 22.04. A highlight
of new features provided by AppArmor 3.0 include:

- Policy now must declare the feature abi it was developed for if it is to
  use any new features. This ensures that old policy will not become
  incompatible with new kernels that support additional AppArmor features.
- The use of profile names that are based on pathnames are deprecated.
- Support for new kernel features (requires appropriate features abi
  tagging in policy)
  - upstream v8 network socket rules
  - xattr attachment conditionals
  - capabilities PERFMON and BPF
- Improved compiler warnings and semantic checks
- aa-status rewritten in C (previously was python) with additional features
  - supports use in systems/images where python is not available
  - supports kill, unconfined and mixed profile modes
- Rewritten aa-notify (previously was perl, now python3)
  - shared backend with other python tools
  - support use of aa.CONFDIR instead of hard coded /etc/apparmor
  - improved message layout
- Improved support for kernels that support LSM stacking
- New utility aa-features-abi to extract and work with kernel abi features
- New utility aa-load to load binary policy without calling the
  apparmor_parser
- Support for profile modes
  - enforce (default when no mode flag is supplied)
  - kill (experimental)
  - unconfined (experimental)

The use of the new AppArmor profile feature ABI includes a default
configuration (for the Ubuntu packaged version of AppArmor proposed in this
FFE) for the AppArmor features within the 5.4 Linux kernel - this ensures
that all profiles provided in AppArmor3 for groovy will conform to this
feature set and that upgrades to the kernel version (say to 5.8) that may
include newer AppArmor confinement features will not result in additional
policy denials as a result (since say the existing profile did not specify
a rule for a new AppArmor feature which is now supported by the upgraded
kernel). This ensures that there will be no regressions in application
behaviour as a result of AppArmor kernel feature upgrades.

TESTING

This has been extensively tested...

[Alex Murray (alexmurray)]

Apologies for posting the description as a comment above...

[Jamie Strandboge (jdstrand)]

FYI, we're looking at the autopkgtest dbus issue now.

[Jamie Strandboge (jdstrand)]

FYI, the fix for the dbus issue is https://gitlab.com/apparmor/apparmor/-/merge_requests/625. We're preparing an ubuntu2 upload now.

[Jamie Strandboge (jdstrand)]

FYI, 3.0.0~beta1-0ubuntu3 should address the dbus autopkgtest issue.

[Jamie Strandboge (jdstrand)]

FYI, I accidentally violated the FFe process and uploaded (with a subsequent binary copy) to groovy-proposed. None of that migrated, so I deleted what was in groovy-proposed and am now attaching the debdiff, which has patches to pass proposed migration (we believe). Sorry for the snafu.

[Iain Lane (laney)]

Just to confirm, your intention (barring bugs) is that there should be no breakage for existing apparmor profiles and consumers of the rewritten tools?

If so, I think this should still be fine at this stage.

[Alex Murray (alexmurray)]

Yes (barring bugs), there is no intention to break anything :)

[Iain Lane (laney)]

OK, go for it!

[Jamie Strandboge (jdstrand)]

Thanks! Uploaded: https://launchpad.net/ubuntu/+source/apparmor/3.0.0~beta1-0ubuntu5

[Christian Ehrhardt  (paelzer)]

I knew from my former tests:
1. apparmor 3.0 = bad
2. downgrading to 2.13.3-7ubuntu6 and back up to 3.0 = good
3. aa-enforce + service restart = good

I checked the logs on the affected systems how this got into the bad state:

$ grep -E 'configure (lib)?(apparmor|libvirt)' /var/log/dpkg.log
2020-09-16 05:56:09 configure libapparmor1:amd64 3.0.0~beta1-0ubuntu1 <none>
2020-09-16 05:56:18 configure apparmor:amd64 3.0.0~beta1-0ubuntu1 <none>
2020-09-16 05:57:31 configure libvirt-daemon-system-systemd:amd64 6.6.0-1ubuntu2 <none>
2020-09-16 05:57:31 configure libvirt0:amd64 6.6.0-1ubuntu2 <none>
2020-09-16 05:57:33 configure libvirt-clients:amd64 6.6.0-1ubuntu2 <none>
2020-09-16 05:57:36 configure libvirt-daemon:amd64 6.6.0-1ubuntu2 <none>
2020-09-16 05:57:36 configure libvirt-daemon-driver-qemu:amd64 6.6.0-1ubuntu2 <none>
2020-09-16 05:57:36 configure libvirt-daemon-system:amd64 6.6.0-1ubuntu2 <none>
2020-09-16 05:58:05 configure apparmor-utils:amd64 3.0.0~beta1-0ubuntu1 <none>
2020-09-17 14:04:17 configure libvirt-daemon-system-dbgsym:amd64 6.6.0-1ubuntu2 <none>
2020-09-17 14:04:17 configure libvirt0-dbgsym:amd64 6.6.0-1ubuntu2 <none>
2020-09-17 14:04:17 configure libvirt-daemon-driver-qemu-dbgsym:amd64 6.6.0-1ubuntu2 <none>
2020-09-17 14:04:17 configure libvirt-clients-dbgsym:amd64 6.6.0-1ubuntu2 <none>
2020-09-17 14:04:17 configure libvirt-daemon-dbgsym:amd64 6.6.0-1ubuntu2 <none>
2020-09-22 06:56:34 configure apparmor:amd64 3.0.0~beta1-0ubuntu5 <none>

It seems I had:
1. groovy container
2. upgrade to proposed (including libapparmor1 / apparmor 3.0)
3. install libvirt

I was trying to recreate the above with a new container as of today:
1. groovy container (2.13.3-7ubuntu6, all still confined)
2. upgrade to proposed (3.0.0~beta1-0ubuntu5, all still confined)
3. install libvirt (confinement working well)

Hmm, something must have been different.
I know I have used container snapshots when I ran into that - I need to sort out in what order that happened and if it would occur again.

[Christian Ehrhardt  (paelzer)]

Sorry, while being about evaluating the new apparmor this got posted to the wrong bug :-/

[Jamie Strandboge (jdstrand)]

FYI, there was a components mismatch where apparmor-notify pulled python3-notify2 (and its Depends) into main. For now, I've demoted apparmor-notify to universe and adjusted the seed (in practical terms, the security team will fix bugs in apparmor-notify regardless of where it lives). We might revisit promoting apparmor-notify at a future date.

[Launchpad Janitor (janitor)]

This bug was fixed in the package apparmor - 3.0.0~beta1-0ubuntu6

---------------
apparmor (3.0.0~beta1-0ubuntu6) groovy; urgency=medium

  * Drop d/p/lp1824812.patch: this patch was only needed with 2.13 and not
    3.0. With AppArmor 3, the patch ends up setting SFS_MOUNTPOINT to the
    wrong directory in is_container_with_internal_policy(), which causes
    policy to always fail to load in containers. Thanks to Christian Ehrhardt
    for the analysis. (LP: #1895967)

apparmor (3.0.0~beta1-0ubuntu5) groovy; urgency=medium

  [ John Johansen ]
  * d/p/fix-parser-to-emit-proc-attr-access-for-all-situations.patch:
    fix-automatic-adding-of-rule-for-change-hat-iface.patch fixed the
    parser to emit rules needed for change_hat in the hat profiles but
    broke the rule being emitted for the parent profile, this fixes it for
    both so that it is emitted for any profile that is a hat or that
    contains a hat.
  * d/p/fix-change-profile-stack-abstraction.patch: fix the change_profile
    abstraction so that it allows access to the apparmor attribute paths
    under LSM stacking.

apparmor (3.0.0~beta1-0ubuntu2) groovy; urgency=medium

  [ John Johansen ]
  * d/p/fix-automatic-adding-of-rule-for-change-hat-iface.patch: fix
    parser not adding a rule to profiles if they are a hat or contain hats
    granting write access to the kernel interfaces.

apparmor (3.0.0~beta1-0ubuntu1) groovy; urgency=medium

  [ John Johansen ]
  * New upstream release (LP: #1895060, LP: #1887577, LP: #1880841)
  * Drop all patches backported from upstream: applied in 3.0
  * d/p/policy-provide-example-and-base-abi-to-pin-pre-3.0-p.patch: provide
    example and base abi to pin pre 3.0 policy
  * d/p/ubuntu/enable-pinning-of-pre-AppArmor-3.x-poli.patch: enable pinning
    of pre AppArmor 3.x policy
  * drop d/p/debian/dont-include-site-local-with-dovecot.patch: no longer
    needed with upstream 'include if exists'

  [ Steve Beattie ]
  * d/p/parser-fix_cap_match.patch: fix cap match to work correctly, important
    now that groovy has a 5.8 kernel.
  * d/apparmor-profiles.install:
    + adjust for renamed postfix profiles
    + add usr.bin.dumpcap and usr.bin.mlmmj-receive to extra-profiles
    + remove usr.sbin.nmbd and usr.sbin.smbd from extra-profiles (already in
      apparmor-profiles)
  * d/apparmor.install: include abi/ directory and tunables/etc.
  * d/apparmor.manpages: add apparmor_xattrs.7 manpage
  * d/control:
    + apparmor-utils: no more shipped perl tools, drop perl dependency
    + apparmor-notify: aa-notify was converted to python3 from perl; adjust
      -notify dependencies to compensate
  * d/p/fix-tests-regression-apparmor-prologue-inc-settest.patch:
    fix sed expression in settest()

  [ Emilia Torino ]
  * Removing Ubuntu specific chromium-browser profile. This is safe to do
    since groovy's chromium-browser deb installs the snap. If apparmor3
    is backported to 18.04 or earlier, the profile will need to be taken
    into consideration
    - d/profiles/chromium-browser: remove chromium-browser profile
    - d/apparmor-profiles.postinst: remove postinst script as it only
      contains chromium-browser related functionallity.
    ...