auditctl - phpMan

AUDITCTL:(8) System Administration Utilities AUDITCTL:(8)

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

SYNOPSIS
auditctl [options]

DESCRIPTION
The auditctl program is used to control the behavior, get status, and add or delete
rules into the 2.6 kernel’s audit system.

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.

-e [0|1]
Set enabled flag. This can be used to temporarily disable auditing or re-
enable it.

-f [0..2]
Set failure flag 0=silent 1=printk 2=panic. This option lets you determine
how you want the kernel to handle critical errors. Example conditions where
this flag is consulted includes: transmission errors to userspace audit dae-
mon, 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

-l List all rules 1 per line.

-k <key>
Set a filter key on a filesystem watch. The filterkey is an arbitrary string
of text that can be up to 31 bytes long. It can uniquely identify the audit
records produced by the watch.

-m text
Send a user-space message into the audit system. This can only be done by
the root user.

-p [r|w|x|a]
Set permissions filter for a file system watch. r=read, w=write, x=execute,
a=append.

-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 com-
ments 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 preceeded by auditctl (since auditctl is the one execut-
ing the file).

-s Report status

-a <l,a>
Append rule to the end of <l>ist with <a>ction. Please note the comma sepa-
rating the two values. Omitting it will cause errors. 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.

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

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 cre-
ated.

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, and pid. All
other fileds will be treated as non-matching.

watch Add a rule to the file system watch filter list. This list is
used to filter events that originate from file system watches.
You can use syscall matching with this list, but the only
syscalls that are meaningful are I/O related.

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.

possible Allocate an audit context for the new task, and always fill it
in at syscall entry time. This makes a full syscall record
available if some other part of the kernel decides it should be
recorded. This option is intended for use with file system
auditing. For example, you could use this with the open syscall
and set a file system watch for a specific file. In this case,
you will not get an audit event for each call to open - just the
ones that the files system watch triggers on.

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

-A <l,a>
Add rule to the beginning <l>ist with <a>ction

-d <l,a>
Delete rule from <l>ist with <a>ction. The rule is deleted only if it
exactly matches syscall name and field names.

-D Delete all rules and watches.

-S [Syscall name or number|all]
Any syscall name or number may be used. The word ’all’ may also be used. If
this 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. Doing so improves
performance since fewer rules need to be evaluated.

-F [n=v | n!=v]
Build a rule field: name = value. You may have multiple fields passed on a
command line. Each one must start with -F. You may have up to 64 fields
passed on a single commandline. Each field equation is anded with each other
to trigger an audit record. There are 2 operators supported - equal and not
equal. Fields that take a user ID may instead have the user’s name; the pro-
gram will convert the name to user ID. The same is true of group names.
Valid fields are:

pid Process ID

uid User ID

euid Effective User ID

suid Set User ID

fsuid Filesystem User ID

gid Group ID

egid Effect Group ID

sgid Set Group ID

fsgid Filesystem Group ID

auid The original ID the user logged in with. Its an abbreviation of
audit uid.

pers OS Personality Number

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.

devmajor Device Major Number

devminor Device Minor Number

inode Inode Number

exit Exit value from a syscall

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

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.

-t <syscall>
Translate syscall number to syscall name. No other task is performed. Also
note that you can use the -F arch=xxx to set the syscall table for transla-
tion. If you use this, it must be before the -t parameter or the machine’s
native type will be used.

-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. Wild-
cards are not supported either and will generate a warning. The way that
watches work is by tracking the inode internally. This means that if you put
a watch on a directory, you will see what appears to be file events, but it
is really just the updating of meta data. You might miss a few events by
doing this. If you need to watch all files in a directory, its recommended
to place an individual watch on each file. Unlike syscall auditing rules,
watches do not impact performance based on the number of rules sent to the
kernel.

-W <path>
Remove a watch for the file system object at <path>

EXAMPLES
To see all syscalls made by a program:

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

To see files opened by a specific user:

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

To see unsuccessful open call’s:

auditctl -a exit,always -S open -F success!=0