peculiar disappearance of most audit rules

[pg@aud.list.sabi.co.UK (Peter Grandi)]

Hi, I have started using 'auditd', mostly to monitor various directories
where packages get installed to check for changes in their contents,
with rules like:

  -w /bin                         -p wa -k pkg-s
  -w /boot                        -p wa -k pkg-s
  -w /etc                         -p wa -k pkg-s
  -w /lib                         -p wa -k pkg-s
  -w /lib32                       -p wa -k pkg-s
  -w /lib64                       -p wa -k pkg-s
  -w /opt                         -p wa -k pkg-s
  -w /usr                         -p wa -k pkg-s

  -w /fs/sozan/loc                -p wa -k pkg-l
  -w /fs/sozan/loc32-el5          -p wa -k pkg-l
  -w /fs/sozan/loc64-u12          -p wa -k pkg-l
  -w /fs/sozan/com                -p wa -k pkg-l
  -w /fs/sozan/com32-el5          -p wa -k pkg-l
  -w /fs/sozan/com64-u12          -p wa -k pkg-l

After setting them, I can verify that for example creating, updating and
deleting a file in '/boot' or '/opt' gets reported.

Wheat then happens is that even if I set 'auditctl -e 2' some of the
rules disappear, usually at around the same time as 'cron.daily' scripts
run, and some more disappear later. This usually seems to relate to
times where there some significant IO activity ('mlocate' scan, backup),
but this is a guess.

For example:

  time->Thu Apr 17 07:58:44 2014
  type=CONFIG_CHANGE msg=audit(1397717924.255:37148): op="remove rule" dir="/boot" key="pkg-s" list=4 res=1
  time->Thu Apr 17 07:59:04 2014
  type=CONFIG_CHANGE msg=audit(1397717944.762:37151): op="remove rule" dir="/opt" key="pkg-s" list=4 res=1
  time->Thu Apr 17 10:01:02 2014
  type=CONFIG_CHANGE msg=audit(1397725262.301:37157): op="remove rule" dir="/fs/sozan/loc64-u12" key="pkg-l" list=4 res=1
  time->Thu Apr 17 10:01:02 2014
  type=CONFIG_CHANGE msg=audit(1397725262.301:37156): op="remove rule" dir="/fs/sozan/loc32-el5" key="pkg-l" list=4 res=1

There is no equivalent line in 'dmesg'.

I understand that the 'audit' kernel modules may remove rules if they
refer to invalid paths, but all the relevant directories do exist, as
for example '/boot' and '/opt' are the standard usual directories in the
"root" tree itself:

  $  ls -ldn /boot /opt /fs/sozan/loc64-u12 /fs/sozan/loc32-el5
  drwxr-xr-x 3 0 0 4096 Apr 21 07:22 /boot
  drwxrwsr-x 7 1 1   61 Jul 30  2011 /fs/sozan/loc32-el5
  drwxrwsr-x 5 1 1   39 Oct  4  2011 /fs/sozan/loc64-u12
  drwxr-xr-x 7 0 0 4096 Apr 20 14:52 /opt

  $  df /boot/. /opt/. /fs/sozan/loc64-u12/. /fs/sozan/loc32-el5/.
  Filesystem     1M-blocks  Used Available Use% Mounted on
  /dev/sda3          24815 16853      4106  81% /
  /dev/sda3          24815 16853      4106  81% /
  /dev/sda6          90048 82355      7694  92% /fs/sozan
  /dev/sda6          90048 82355      7694  92% /fs/sozan

This is happening on two similarly configured Ubuntu 12.04 systems with
both 3.2 and 3.11 Ubuntu "official" kernels. I also have an AppArmor
configuration which seem to trigger bugs in AppArmor, but all the
relative profiles are essentially unchanged.

Eventually around almost all of the rules I have set "disappear". For
example of all these rules:

  LIST_RULES: exit,always dir=/fs/sozan/search (0x10) perm=r key=pkg-r
  LIST_RULES: exit,always dir=/fs/sozan/mlocate (0x11) perm=r key=pkg-r
  ....
  LIST_RULES: exit,always dir=/bin (0x4) perm=wa key=pkg-s
  LIST_RULES: exit,always dir=/boot (0x5) perm=wa key=pkg-s
  LIST_RULES: exit,always dir=/etc (0x4) perm=wa key=pkg-s
  LIST_RULES: exit,always dir=/lib (0x4) perm=wa key=pkg-s
  LIST_RULES: exit,always dir=/lib32 (0x6) perm=wa key=pkg-s
  LIST_RULES: exit,always dir=/lib64 (0x6) perm=wa key=pkg-s
  LIST_RULES: exit,always dir=/opt (0x4) perm=wa key=pkg-s
  LIST_RULES: exit,always dir=/usr (0x4) perm=wa key=pkg-s
  LIST_RULES: exit,always dir=/fs/sozan/loc (0xd) perm=wa key=pkg-l
  LIST_RULES: exit,always dir=/fs/sozan/loc32-el5 (0x13) perm=wa key=pkg-l
  LIST_RULES: exit,always dir=/fs/sozan/loc64-u12 (0x13) perm=wa key=pkg-l
  LIST_RULES: exit,always dir=/fs/sozan/com (0xd) perm=wa key=pkg-l
  LIST_RULES: exit,always dir=/fs/sozan/com32-el5 (0x13) perm=wa key=pkg-l
  LIST_RULES: exit,always dir=/fs/sozan/com64-u12 (0x13) perm=wa key=pkg-l

Only the first two have not "disappeared" on one of the systems.

This is rather peculiar, please let me know if it is a configuration
error, an issue, and any fixes or workaround if available (other than
running 'auditctl -R /etc/audit/audit.rules' every few minutes via CRON).