### VERIFICATION DONE FOCAL ###
sudo add-apt-repository ppa:apparmor-dev/mqueue-dev
sudo apt update
# exchange keypair ssh
scp linux-* ubuntu@x.x.x.x:~
sudo dpkg -i linux*
sudo apt --fix-broken install
# edit /etc/default/grub
GRUB_DEFAULT='Advanced options for Ubuntu>Ubuntu, with Linux 5.4.0-131-generic'
sudo update-grub
restart/reboot machine
sudo apt-get upgrade apparmor
# go find menu entry and update grub
/boot/boot.cfg
# menuentry 'Ubuntu, with Linux 5.4.0-131-generic'
# execute command
GRUB_DEFAULT='Advanced options for Ubuntu>Ubuntu, with Linux 5.4.0-131-generic'
# should output
supports mqueue
sudo apt install ubuntu-dev-tools -y
pull-ppa-source --ppa georgiag/mqueue-sru apparmor focal
sudo apt-get install autoconf libtool -y
cd ./libraries/libapparmor/
./autogen.sh
export PYTHONPATH=/tmp/apparmor-2.13.3/libraries/libapparmor/swig/python
export PYTHON=/usr/bin/python3
export PYTHON_VERSION=3
export PYTHON_VERSIONS=python3
export USE_SYSTEM=1 make
./configure
sudo apt-get install flex dejagnu
make
sudo make check
sudo make install
cd binutils
make
make check
make install
cd ./libraries/libapparmor
sh ./autogen.sh
sh ./configure
make
make check
make install
cd parser
$ make # depends on libapparmor having been built first
$ make check
# run unit tests
cd /tests/regession/apparmor/
sudo make tests
sudo su
echo "
abi <kernel>,
include <tunables/global>
/tmp/apparmor-2.13.3/tests/regression/apparmor/posix_mq_rcv {
include <abstractions/base>
/tmp/apparmor-2.13.3/tests/regression/apparmor/posix_mq_snd ux,
}
" | apparmor_parser -q -r
# run command
./posix_mq_rcv -c ./posix_mq_snd
FAIL - could not open mq: Permission denied
# we see this fail error
# make sure there is enough permissions to execute
sudo chmod 777 posix_mq_rcv
./posix_mq_rcv -c ./posix_mq_snd
PASS
### VERIFICATION DONE FOCAL ###
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You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to apparmor in Ubuntu.
https://bugs.launchpad.net/bugs/1728130
Title:
Policy needs improved feature versioning to ensure it is correctly
being applied
Status in apparmor package in Ubuntu:
Confirmed
Status in apparmor source package in Focal:
Fix Committed
Bug description:
[ Impact ]
Currently allows pinning a single feature abi or running in a
developer mode where the full abi available of the current kernel is
enforced.
However this can result in breaking applications in undesirable ways.
If an application is shipped with its own policy, that policy might be
different than the pinned feature abi, which can either result in
denials because features the policy was not developed for are being
enforced.
If the feature version is not pinned then the most recent kernel abi
is taken and applied to policy, which has not been updated. This can
result in denials for userspace effectively breaking userspace. This
is less than ideal for most users as it leads to a bad experience than
they have not opted into and can lead to them disabling security
protections.
[ Test Plan ]
The test can be done with several features. Here we are using mqueue as an
example.
Verify that the kernel that has mqueue mediation support:
root@ubuntu:~# [ -e /sys/kernel/security/apparmor/features/ipc/posix_mqueue ]
&& echo "supports mqueue"
supports mqueue
cd /tmp
pull-ppa-source --ppa georgiag/mqueue-sru apparmor focal
cd apparmor-2.13.3/tests/regression/apparmor/
USE_SYSTEM=1 make
Using the parser from the mqueue-sru PPA, load the profile.
echo "
abi <kernel>,
include <tunables/global>
/tmp/apparmor-2.13.3/tests/regression/apparmor/posix_mq_rcv {
include <abstractions/base>
/tmp/apparmor-2.13.3/tests/regression/apparmor/posix_mq_snd ux,
}
" | apparmor_parser -q -r
Run the test, which should fail.
./posix_mq_rcv -c ./posix_mq_snd
FAIL - could not open mq: Permission denied
Now use an abi that does not have mqueue. This simulates a scenario
where a policy was developed before mqueue support was added, so posix
message queues should be allowed by default.
echo "
abi <abi/2.13>,
include <tunables/global>
/tmp/apparmor-2.13.3/tests/regression/apparmor/posix_mq_rcv {
include <abstractions/base>
/tmp/apparmor-2.13.3/tests/regression/apparmor/posix_mq_snd ux,
}
" | apparmor_parser -q -r
Run the test again, it should pass.
./posix_mq_rcv -c ./posix_mq_snd
PASS
[ Where problems could occur ]
ABI pinning forces policies that don't have abi specified in their
profile to use the ABI pinned in parser.conf. When the ABI is pinned
and the user is trying to use mediation that is not in the pinned ABI,
they might be confused why it is always being allowed. This can be
circumvented by specifying the correct abi in the profile.
[ Other Info ]
The patches for focal (apparmor-2.13) can be found at:
https://launchpad.net/~georgiag/+archive/ubuntu/mqueue-sru/
apparmor-3.0 already has this feature.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/1728130/+subscriptions
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