Provided by: auditd_2.4.5-1ubuntu2_i386 bug

NAME

       auditctl - a utility to assist controlling the kernel's audit system

SYNOPSIS

       auditctl [options]

DESCRIPTION

       The  auditctl  program  is  used to configure kernel options related to
       auditing, to see status of the configuration, and to load discretionary
       audit rules.

CONFIGURATION OPTIONS

       -b backlog
              Set  max  number  of  outstanding  audit buffers allowed (Kernel
              Default=64) If  all  buffers  are  full,  the  failure  flag  is
              consulted by the kernel for action.

       --backlog_wait_time wait_time
              Set  the time for the kernel to wait (Kernel Default 60*HZ) when
              the backlog_limit is reached before queuing more audit events to
              be  transferred  to  auditd.  The number must be greater than or
              equal to zero and less that 10 times the default value.

       -c     Continue loading rules in spite of an error. This summarizes the
              results  of loading the rules. The exit code will not be success
              if any rule fails to load.

       -D     Delete all rules and watches. This can take a key  option  (-k),
              too.

       -e [0..2]
              Set  enabled  flag.  When  0  is  passed,  this  can  be used to
              temporarily disable auditing. When 1 is passed as  an  argument,
              it will enable auditing. To lock the audit configuration so that
              it can't be changed, pass a  2  as  the  argument.  Locking  the
              configuration  is intended to be the last command in audit.rules
              for anyone wishing this feature to be  active.  Any  attempt  to
              change  the  configuration  in  this  mode  will  be audited and
              denied. The configuration can only be changed by  rebooting  the
              machine.

       -f [0..2]
              Set failure mode 0=silent 1=printk 2=panic. This option lets you
              determine how you want the kernel  to  handle  critical  errors.
              Example  conditions where this mode may have an effect includes:
              transmission errors to userspace  audit  daemon,  backlog  limit
              exceeded,  out  of  kernel  memory, and rate limit exceeded. The
              default value is 1. Secure environments will  probably  want  to
              set this to 2.

       -h     Help

       -i     Ignore  errors  when  reading  rules  from  a  file. This causes
              auditctl to always return a success exit code.

       --loginuid-immutable
              This option tells the kernel to make loginuids unchangeable once
              they are set. Changing loginuids requires CAP_AUDIT_CONTROL. So,
              its not something  that  can  be  done  by  unprivileged  users.
              Setting  this  makes  loginuid  tamper-proof, but can cause some
              problems in certain kinds of containers.

       -q mount-point,subtree
              If you have an existing directory watch and bind or  move  mount
              another  subtree  in  the  watched subtree, you need to tell the
              kernel to make the  subtree  being  mounted  equivalent  to  the
              directory  being  watched.  If the subtree is already mounted at
              the  time  the  directory  watch  is  issued,  the  subtree   is
              automatically   tagged  for  watching.  Please  note  the  comma
              separating the two values. Omitting it will cause errors.

       -r rate
              Set limit in messages/sec (0=none). If this rate is non-zero and
              is  exceeded,  the  failure  flag is consulted by the kernel for
              action. The default value is 0.

       -R file
              Read rules from a file. The rules must be 1 per line and in  the
              order  that  they  are  to be executed in. The rule file must be
              owned by root and not readable by other  users  or  it  will  be
              rejected.  The  rule file may have comments embedded by starting
              the line with a '#' character. Rules that are read from  a  file
              are  identical  to  what you would type on a command line except
              they are not preceded by auditctl (since  auditctl  is  the  one
              executing  the  file) and you would not use shell escaping since
              auditctl is reading the file instead of bash.

       -t     Trim the subtrees after a mount command.

STATUS OPTIONS

       -l     List all rules 1 per line. Two more options may be given to this
              command.  You  can  give  either a key option (-k) to list rules
              that match a key or a (-i) to have a0 through a3 interpretted to
              help determine the syscall argument values are correct .

       -m text
              Send  a  user space message into the audit system. This can only
              be done if you have  CAP_AUDIT_WRITE  capability  (normally  the
              root user has this). The resulting event will be the USER type.

       -s     Report the kernel's audit subsystem status. It will tell you the
              in-kernel values that can be set by -e, -f, -r, and -b  options.
              The  pid  value  is the process number of the audit daemon. Note
              that a pid of 0 indicates that the audit daemon is not  running.
              The  lost  entry  will tell you how many event records that have
              been discarded due to the kernel audit  queue  overflowing.  The
              backlog  field tells how many event records are currently queued
              waiting for auditd to read them. This option can be followed  by
              the -i to get a couple fields interpreted.

       -v     Print the version of auditctl.

RULE OPTIONS

       -a [list,action|action,list]
              Append  rule  to  the  end  of list with action. Please note the
              comma separating the two values. Omitting it will cause  errors.
              The  fields  may  be in either order. It could be list,action or
              action,list. The following describes the valid list names:

              task        Add a rule to the per task list. This rule  list  is
                          used  only  at  the  time  a task is created -- when
                          fork() or clone() are called  by  the  parent  task.
                          When  using  this  list,  you should only use fields
                          that are known at task creation time,  such  as  the
                          uid, gid, etc.

              exit        Add  a  rule  to the syscall exit list. This list is
                          used upon exit from a system call to determine if an
                          audit event should be created.

              user        Add  a  rule  to  the user message filter list. This
                          list  is  used  by  the  kernel  to  filter   events
                          originating  in  user  space before relaying them to
                          the audit daemon. It should be noted that  the  only
                          fields  that  are  valid  are:  uid, auid, gid, pid,
                          subj_user, subj_role, subj_type, subj_sen, subj_clr,
                          and  msgtype.  All  other  fields will be treated as
                          non-matching. It should be understood that any event
                          originating  from user space from a process that has
                          CAP_AUDIT_WRITE will  be  recorded  into  the  audit
                          trail.  This means that the most likely use for this
                          filter is with rules that have an  action  of  never
                          since  nothing  has to be done to allow events to be
                          recorded.

              exclude     Add a rule to the event type exclusion filter  list.
                          This  list  is used to filter events that you do not
                          want to see. For example, if you do not want to  see
                          any  avc  messages,  you  would  using  this list to
                          record that. The message type that you do  not  wish
                          to see is given with the msgtype field.

       The following describes the valid actions for the rule:

              never       No audit records will be generated. This can be used
                          to suppress event generation. In general,  you  want
                          suppressions  at  the top of the list instead of the
                          bottom. This is because the event  triggers  on  the
                          first matching rule.

              always      Allocate  an  audit  context,  always  fill it in at
                          syscall entry time, and always write out a record at
                          syscall exit time.

       -A list,action
              Add rule to the beginning list with action.

       -C [f=f | f!=f]
              Build  an  inter-field comparison rule: field, operation, field.
              You may pass multiple comparisons on a single command line. Each
              one  must start with -C. Each inter-field equation is anded with
              each other as well as equations starting with -F to  trigger  an
              audit  record.  There are 2 operators supported - equal, and not
              equal. Valid fields are:

              auid, uid, euid, suid, fsuid,  obj_uid;  and  gid,  egid,  sgid,
              fsgid, obj_gid

              The  two  groups  of  uid  and  gid  cannot  be  mixed.  But any
              comparison within the group can be made. The obj_uid/gid  fields
              are  collected  from  the  object of the event such as a file or
              directory.

       -d list,action
              Delete rule from list with action. The rule is deleted  only  if
              it  exactly  matches  syscall  name(s)  and every field name and
              value.

       -F [n=v | n!=v | n<v | n>v | n<=v | n>=v | n&v | n&=v]
              Build a rule field: name, operation, value. You may have  up  to
              64  fields  passed on a single command line. Each one must start
              with -F. Each field equation is anded with each other  (as  well
              as equations starting with -C) to trigger an audit record. There
              are 8 operators supported - equal, not equal, less than, greater
              than,  less  than or equal, and greater than or equal, bit mask,
              and bit test respectively. Bit test will "and"  the  values  and
              check  that  they  are  equal,  bit mask just "ands" the values.
              Fields that take a user ID may instead have the user's name; the
              program  will  convert  the name to user ID. The same is true of
              group names. Valid fields are:

              a0, a1, a2, a3
                          Respectively, the first 4 arguments  to  a  syscall.
                          Note  that  string arguments are not supported. This
                          is because the kernel is passed  a  pointer  to  the
                          string. Triggering on a pointer address value is not
                          likely to work. So, when using this, you should only
                          use  on  numeric  values.  This is most likely to be
                          used on  platforms  that  multiplex  socket  or  IPC
                          operations.

              arch        The CPU architecture of the syscall. The arch can be
                          found doing 'uname -m'. If you do not know the  arch
                          of  your  machine  but  you  want  to use the 32 bit
                          syscall table and your machine supports 32 bit,  you
                          can  also  use b32 for the arch. The same applies to
                          the 64 bit syscall table, you can use b64.  In  this
                          way,  you  can  write  rules  that are somewhat arch
                          independent because the family  type  will  be  auto
                          detected. However, syscalls can be arch specific and
                          what is available on x86_64, may not be available on
                          ppc. The arch directive should precede the -S option
                          so that auditctl knows which internal table  to  use
                          to look up the syscall numbers.

              auid        The  original  ID  the  user  logged in with. Its an
                          abbreviation of audit uid. Sometimes its referred to
                          as  loginuid. Either the user account text or number
                          may be used.

              devmajor    Device Major Number

              devminor    Device Minor Number

              dir         Full Path of Directory to watch. This will  place  a
                          recursive  watch  on  the  directory  and  its whole
                          subtree. It can only be used on exit list. See "-w".

              egid        Effective Group ID. May be  numeric  or  the  groups
                          name.

              euid        Effective  User  ID.  May  be  numeric  or  the user
                          account name.

              exit        Exit value from a syscall. If the exit  code  is  an
                          errno, you may use the text representation, too.

              fsgid       Filesystem  Group  ID.  May be numeric or the groups
                          name.

              fsuid       Filesystem User ID.  May  be  numeric  or  the  user
                          account name.

              filetype    The  target  file's  type.  Can be either file, dir,
                          socket, link, character, block, or fifo.

              gid         Group ID. May be numeric or the groups name.

              inode       Inode Number

              key         This is another way of setting  a  filter  key.  See
                          discussion above for -k option.

              msgtype     This  is  used  to match the event's record type. It
                          should only be used on the exclude  or  user  filter
                          lists.

              obj_uid     Object's UID

              obj_gid     Object's GID

              obj_user    Resource's SE Linux User

              obj_role    Resource's SE Linux Role

              obj_type    Resource's SE Linux Type

              obj_lev_low Resource's SE Linux Low Level

              obj_lev_high
                          Resource's SE Linux High Level

              path        Full  Path  of File to watch. It can only be used on
                          exit list.

              perm        Permission filter for file operations. See "-p".  It
                          can  only  be  used  on  exit list. You can use this
                          without specifying a syscall  and  the  kernel  will
                          select  the  syscalls  that  satisfy the permissions
                          being requested.

              pers        OS Personality Number

              pid         Process ID

              ppid        Parent's Process ID

              subj_user   Program's SE Linux User

              subj_role   Program's SE Linux Role

              subj_type   Program's SE Linux Type

              subj_sen    Program's SE Linux Sensitivity

              subj_clr    Program's SE Linux Clearance

              sgid        Saved Group ID. See getresgid(2) man page.

              success     If the exit value is >= 0 this is true/yes otherwise
                          its  false/no.  When  writing  a  rule,  use a 1 for
                          true/yes and a 0 for false/no

              suid        Saved User ID. See getresuid(2) man page.

              uid         User ID. May be numeric or the user account name.

       -k key Set a filter key  on  an  audit  rule.  The  filter  key  is  an
              arbitrary string of text that can be up to 31 bytes long. It can
              uniquely identify the audit records produced by a rule.  Typical
              use  is  for when you have several rules that together satisfy a
              security requirement. The key value  can  be  searched  on  with
              ausearch  so  that no matter which rule triggered the event, you
              can find its results. The key can also be  used  on  delete  all
              (-D)  and  list  rules (-l) to select rules with a specific key.
              You may have more than one key on a rule if you want to be  able
              to  search  logged  events  in  multiple  ways or if you have an
              audispd plugin that uses a key to aid its analysis.

       -p [r|w|x|a]
              Describe the permission access type that  a  file  system  watch
              will trigger on. r=read, w=write, x=execute, a=attribute change.
              These permissions are not the  standard  file  permissions,  but
              rather the kind of syscall that would do this kind of thing. The
              read & write syscalls are omitted from this set since they would
              overwhelm  the  logs.  But  rather for reads or writes, the open
              flags are looked at to see what permission was requested.

       -S [Syscall name or number|all]
              Any syscall name or number may be used. The word 'all' may  also
              be  used.  If the given syscall is made by a program, then start
              an audit record. If a field rule is  given  and  no  syscall  is
              specified, it will default to all syscalls. You may also specify
              multiple syscalls in the same rule by using multiple -S  options
              in  the  same  rule.  Doing  so improves performance since fewer
              rules need to be evaluated. Alternatively, you may pass a  comma
              separated list of syscall names. If you are on a bi-arch system,
              like x86_64, you should be aware that auditctl simply takes  the
              text,  looks  it  up  for the native arch (in this case b64) and
              sends that rule to the kernel. If there are no  additional  arch
              directives, IT WILL APPLY TO BOTH 32 & 64 BIT SYSCALLS. This can
              have undesirable effects since there is no  guarantee  that  any
              syscall  has  the  same number on both 32 and 64 bit interfaces.
              You will likely want to control this and write 2 rules, one with
              arch equal to b32 and one with b64 to make sure the kernel finds
              the events that you intend. See the arch  field  discussion  for
              more info.

       -w path
              Insert  a  watch  for the file system object at path. You cannot
              insert a watch to the top level directory. This is prohibited by
              the kernel. Wildcards are not supported either and will generate
              a warning. The way that watches work is by  tracking  the  inode
              internally.  If  you  place  a  watch on a file, its the same as
              using the -F path option on a syscall rule. If you place a watch
              on  a  directory,  its  the same as using the -F dir option on a
              syscall rule. The -w form of writing watches  is  for  backwards
              compatibility  and  the  syscall  based form is more expressive.
              Unlike most  syscall  auditing  rules,  watches  do  not  impact
              performance based on the number of rules sent to the kernel. The
              only valid options when using a watch are the -p and -k. If  you
              need  to  anything  fancy like audit a specific user accessing a
              file, then use the syscall auditing form with the  path  or  dir
              fields.  See  the  EXAMPLES section for an example of converting
              one form to another.

       -W path
              Remove a watch for the file system object at path. The rule must
              match exactly. See -d discussion for more info.

PERFORMANCE TIPS

       Syscall  rules get evaluated for each syscall for every program. If you
       have 10 syscall rules, every program on your system will delay during a
       syscall  while  the  audit system evaluates each rule. Too many syscall
       rules will hurt performance. Try to combine as many as you can whenever
       the filter, action, key, and fields are identical. For example:

       auditctl -a always,exit -S openat -F success=0
       auditctl -a always,exit -S truncate -F success=0

       could be re-written as one rule:

       auditctl -a always,exit -S openat -S truncate -F success=0

       Also, try to use file system auditing wherever practical. This improves
       performance. For example, if you were wanting  to  capture  all  failed
       opens  &  truncates  like above, but were only concerned about files in
       /etc and didn't care about /usr or /sbin,  its  possible  to  use  this
       rule:

       auditctl -a always,exit -S openat -S truncate -F dir=/etc -F success=0

       This  will  be higher performance since the kernel will not evaluate it
       each and every syscall. It will be handled by the  filesystem  auditing
       code and only checked on filesystem related syscalls.

EXAMPLES

       To see all syscalls made by a specific program:

       auditctl -a always,exit -S all -F pid=1005

       To see files opened by a specific user:

       auditctl -a always,exit -S openat -F auid=510

       To see unsuccessful openat calls:

       auditctl -a always,exit -S openat -F success=0

       To watch a file for changes (2 ways to express):

       auditctl -w /etc/shadow -p wa
       auditctl -a always,exit -F path=/etc/shadow -F perm=wa

       To recursively watch a directory for changes (2 ways to express):

       auditctl -w /etc/ -p wa
       auditctl -a always,exit -F dir=/etc/ -F perm=wa

       To see if an admin is accessing other user's files:

       auditctl -a always,exit -F dir=/home/ -F uid=0 -C auid!=obj_uid

FILES

       /etc/audit/audit.rules

SEE ALSO

       audit.rules(7), auditd(8).

AUTHOR

       Steve Grubb