Public bug reported: Symptoms are that cache files in /var/cache/apparmor and profiles in /var/lib/apparmor/profiles are sometimes corrupted after a reboot. We've already fixed several bugs in the apparmor and click-apparmor and made both more robust in the face of corruption, but we've still not found the cause. The corruption can still affect real-world devices: if a profile in /var/lib/apparmor/profiles is corrupted and the cache file is out of date, then the profile won't compile and that app/scope won't start.
Workaround: remove the affected profile and then run 'sudo aa- clickhook'. This obviously is not viable on an end-user device. The investigation is ongoing and this may not be a problem with the kernel at all, so this bug may be retargeted to another project. The security team and the kernel team have discussed this a lot and Colin is currently looking at this. This bug is just so it can be tracked. Here is an excerpt from my latest email to Colin: "I believe I have conclusively ruled out apparmor_parser and aa- clickhook by creating a new 'home/bug/test-with-true.sh'. Here is the test output: http://paste.ubuntu.com/8648109/ Specifically, home/bug/test-with-true.sh changes the interesting parts of the algorithm to: 1. wait for unity8 to start (this ensures the apparmor upstart job is finished) 2. restore apparmor_parser and aa-clickhook, if needed 3. if /home/bug/profiles... exists, perform a diff -Naur /home/bug/profiles... /var/lib/apparmor/profiles and fail if differences (note, apparmor_parser and aa-clickhook were /bin/true during boot so they could not have changed /var/lib/apparmor/profiles) 4. verify the profiles, exit with error if they do not 5. alternately upgrade/downgrade the packages 6. verify the profiles, exit with error if they do not 7. copy the known good profiles in the previous step to /home/bug/profiles... 8. have apparmor_parser and aa-clickhook point to /bin/true 9. reboot 10. go to step 1 In the paste you'll notice that in step 6 the profiles were successfully created by the installation of the packages, then verified, then copied aside, then apparmor_parser and aa-clickhook diverted, then rebooted, only to have the profiles in /var/lib/apparmor/profiles be different than what was copied aside. It would be nice to verify on your device as well (I reproduced several times here) and verify the reproducer algorithm. I think this suggests this is a kernel issue and not userspace. IMPORTANT: you will want to update the reproducer and refollow all of these steps (ie, I updated the scripts, the debs, the sudoers file, etc): $ wget http://people.canonical.com/~jamie/cking/aa-corruption.tar.gz $ tar -zxvf ./aa-corruption.tar.gz ... $ adb push ./aa-corruption.tar.gz /tmp $ adb shell phablet@ubuntu-phablet:~$ cd /tmp phablet@ubuntu-phablet:~$ tar -zxvf ./aa-corruption.tar.gz phablet@ubuntu-phablet:~$ sudo mount -o remount,rw / phablet@ubuntu-phablet:~$ sudo cp ./aa-corruption/etc/sudoers.d/phablet /etc/sudoers.d/ phablet@ubuntu-phablet:~$ sudo mount -o remount,ro / phablet@ubuntu-phablet:~$ sudo cp -a ./aa-corruption/home/bug /home phablet@ubuntu-phablet:~$ exit $ cd ./aa-corruption $ ./test-from-host.sh ... The old script is still in place. Simply adjust ./test-from-host.sh to have: testscript=/home/bug/test.sh #testscript=/home/bug/test-with-true.sh" The kernel team has been able to confirm the symptoms. Related bugs: * bug 1371771 * bug 1371765 * bug 1377338 ** Affects: linux (Ubuntu) Importance: Critical Assignee: Colin Ian King (colin-king) Status: Confirmed ** Description changed: Symptoms are that cache files in /var/cache/apparmor and profiles in /var/lib/apparmor/profiles are sometimes corrupted after a reboot. We've already fixed several bugs in the apparmor and click-apparmor and made both more robust in the face of corruption, but we've still not found the cause. The investigation is ongoing and this may not be a problem with the kernel at all, so this bug may be retargeted to another project. The security team and the kernel team have discussed this a lot and Colin is currently looking at this. This bug is just so it can be tracked. Here is an excerpt from my latest email to Colin: "I believe I have conclusively ruled out apparmor_parser and aa- clickhook by creating a new 'home/bug/test-with-true.sh'. Here is the test output: http://paste.ubuntu.com/8648109/ Specifically, home/bug/test-with-true.sh changes the interesting parts of the algorithm to: 1. wait for unity8 to start (this ensures the apparmor upstart job is finished) 2. restore apparmor_parser and aa-clickhook, if needed 3. if /home/bug/profiles... exists, perform a diff -Naur /home/bug/profiles... - /var/lib/apparmor/profiles and fail if differences (note, apparmor_parser - and aa-clickhook were /bin/true during boot so they could not have changed - /var/lib/apparmor/profiles) + /var/lib/apparmor/profiles and fail if differences (note, apparmor_parser + and aa-clickhook were /bin/true during boot so they could not have changed + /var/lib/apparmor/profiles) 4. verify the profiles, exit with error if they do not 5. alternately upgrade/downgrade the packages 6. verify the profiles, exit with error if they do not 7. copy the known good profiles in the previous step to /home/bug/profiles... 8. have apparmor_parser and aa-clickhook point to /bin/true 9. reboot 10. go to step 1 In the paste you'll notice that in step 6 the profiles were successfully created by the installation of the packages, then verified, then copied aside, then apparmor_parser and aa-clickhook diverted, then rebooted, only to have the profiles in /var/lib/apparmor/profiles be different than what was copied aside. It would be nice to verify on your device as well (I reproduced several times here) and verify the reproducer algorithm. I think this suggests this is a kernel issue and not userspace. IMPORTANT: you will want to update the reproducer and refollow all of these steps (ie, I updated the scripts, the debs, the sudoers file, etc): $ wget http://people.canonical.com/~jamie/cking/aa-corruption.tar.gz $ tar -zxvf ./aa-corruption.tar.gz ... $ adb push ./aa-corruption.tar.gz /tmp $ adb shell phablet@ubuntu-phablet:~$ cd /tmp phablet@ubuntu-phablet:~$ tar -zxvf ./aa-corruption.tar.gz phablet@ubuntu-phablet:~$ sudo mount -o remount,rw / phablet@ubuntu-phablet:~$ sudo cp ./aa-corruption/etc/sudoers.d/phablet /etc/sudoers.d/ phablet@ubuntu-phablet:~$ sudo mount -o remount,ro / phablet@ubuntu-phablet:~$ sudo cp -a ./aa-corruption/home/bug /home phablet@ubuntu-phablet:~$ exit $ cd ./aa-corruption $ ./test-from-host.sh ... The old script is still in place. Simply adjust ./test-from-host.sh to have: testscript=/home/bug/test.sh #testscript=/home/bug/test-with-true.sh" + + + The kernel team has been able to confirm the symptoms. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1387214 Title: file corruption on touch images in rw portions of the filesystem To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1387214/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
