1AUDITD.CONF:(5) System Administration Utilities AUDITD.CONF:(5)
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6 auditd.conf - audit daemon configuration file
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9 The file /etc/audit/auditd.conf contains configuration information spe‐
10 cific to the audit daemon. It should contain one configuration keyword
11 per line, an equal sign, and then followed by appropriate configuration
12 information. The keywords recognized are: log_file, log_format,
13 log_group, flush, freq, num_logs, max_log_file, max_log_file_action,
14 space_left, action_mail_acct, space_left_action, admin_space_left,
15 admin_space_left_action, disk_full_action, and disk_error_action.
16 These keywords are described below.
17 log_file
20 This keyword specifies the full path name to the log file where
21 audit records will be stored. It must be a regular file.
22 log_format
24 The log format describes how the information should be stored on
25 disk. There are 2 options: raw and nolog. If set to RAW, the
26 audit records will be stored in a format exactly as the kernel
27 sends it. If this option is set to NOLOG then all audit informa‐
28 tion is discarded instead of writing to disk. This mode does not
29 affect data sent to the audit event dispatcher.
30 log_group
32 This keyword specifies the group that is applied to the log
33 file's permissions. The default is root. The group name can be
34 either numeric or spelled out.
35 priority_boost
37 This is a non-negative number that tells the audit damon how
38 much of a priority boost it should take. The default is 3. No
39 change is 0.
40 flush Valid values are none, incremental, data, and sync. If set to
42 none, no special effort is made to flush the audit records to
43 disk. If set to incremental, Then the freq parameter is used to
44 determine how often an explicit flush to disk is issued. The
45 data parameter tells the audit damon to keep the data portion of
46 the disk file sync'd at all times. The sync option tells the
47 audit daemon to keep both the data and meta-data fully sync'd
48 with every write to disk.
49 freq This is a non-negative number that tells the audit damon how
51 many records to write before issuing an explicit flush to disk
52 command. this value is only valid when the flush keyword is set
53 to incremental.
54 num_logs
56 This keyword specifies the number of log files to keep if rotate
57 is given as the max_log_file_action. If the number is < 2, logs
58 are not rotated. This number must be 99 or less. The default is
59 0 - which means no rotation. As you increase the number of log
60 files being rotated, you may need to adjust the kernel backlog
61 setting upwards since it takes more time to rotate the files.
62 This is typically done in /etc/audit/audit.rules.
63 dispatcher
65 The dispatcher is a program that is started by the audit daemon
66 when it starts up. It will pass a copy of all audit events to
67 that application's stdin. Make sure you trust the application
68 that you add to this line since it runs with root privileges.
69 disp_qos
71 This option controls whether you want blocking/lossless or non-
72 blocking/lossy communication between the audit daemon and the
73 dispatcher. There is a 128k buffer between the audit daemon and
74 dispatcher. This is good enogh for most uses. If lossy is cho‐
75 sen, incoming events going to the dispatcher are discarded when
76 this queue is full. (Events are still written to disk if
77 log_format is not nolog.) Otherwise the auditd daemon will wait
78 for the queue to have an empty spot before logging to disk. The
79 risk is that while the daemon is waiting for network IO, an
80 event is not being recorded to disk. Valid values are: lossy and
81 lossless. Lossy is the default value.
82 max_log_file
84 This keyword specifies the maximum file size in megabytes. When
85 this limit is reached, it will trigger a configurable action.
86 The value given must be numeric.
87 max_log_file_action
89 This parameter tells the system what action to take when the
90 system has detected that the max file size limit has been
91 reached. Valid values are ignore, syslog, suspend, rotate and
92 keep_logs. If set to ignore, the audit daemon does nothing.
93 syslog means that it will issue a warning to syslog. suspend
94 will cause the audit daemon to stop writing records to the disk.
95 The daemon will still be alive. The rotate option will cause the
96 audit daemon to rotate the logs. It should be noted that logs
97 with higher numbers are older than logs with lower numbers. This
98 is the same convention used by the logrotate utility. The
99 keep_logs option is similar to rotate except it does not use the
100 num_logs setting. This prevents audit logs from being overwrit‐
101 ten.
102 action_mail_acct
104 This option should contain a valid email address or alias. The
105 default address is root. If the email address is not local to
106 the machine, you must make sure you have email properly config‐
107 ured on your machine and network. Also, this option requires
108 that /usr/lib/sendmail exists on the machine.
109 space_left
111 This is a numeric value in megabytes that tells the audit daemon
112 when to perform a configurable action because the system is
113 starting to run low on disk space.
114 space_left_action
116 This parameter tells the system what action to take when the
117 system has detected that it is starting to get low on disk
118 space. Valid values are ignore, syslog, email, exec, suspend,
119 single, and halt. If set to ignore, the audit daemon does noth‐
120 ing. syslog means that it will issue a warning to syslog.
121 Email means that it will send a warning to the email account
122 specified in action_mail_acct as well as sending the message to
123 syslog. exec /path-to-script will execute the script. You can‐
124 not pass parameters to the script. suspend will cause the audit
125 daemon to stop writing records to the disk. The daemon will
126 still be alive. The single option will cause the audit daemon to
127 put the computer system in single user mode. halt option will
128 cause the audit daemon to shutdown the computer system.
129 admin_space_left
131 This is a numeric value in megabytes that tells the audit daemon
132 when to perform a configurable action because the system is run‐
133 ning low on disk space. This should be considered the last
134 chance to do something before running out of disk space. The
135 numeric value for this parameter should be lower than the number
136 for space_left.
137 admin_space_left_action
139 This parameter tells the system what action to take when the
140 system has detected that it is low on disk space. Valid values
141 are ignore, syslog, email, exec, suspend, single, and halt. If
142 set to ignore, the audit daemon does nothing. Syslog means that
143 it will issue a warning to syslog. Email means that it will
144 send a warning to the email account specified in
145 action_mail_acct as well as sending the message to syslog. exec
146 /path-to-script will execute the script. You cannot pass parame‐
147 ters to the script. Suspend will cause the audit daemon to stop
148 writing records to the disk. The daemon will still be alive. The
149 single option will cause the audit daemon to put the computer
150 system in single user mode. halt
151 disk_full_action
153 This parameter tells the system what action to take when the
154 system has detected that the partition to which log files are
155 written has become full. Valid values are ignore, syslog, exec,
156 suspend, single, and halt. If set to ignore, the audit daemon
157 does nothing. Syslog means that it will issue a warning to sys‐
158 log. exec /path-to-script will execute the script. You cannot
159 pass parameters to the script. Suspend will cause the audit
160 daemon to stop writing records to the disk. The daemon will
161 still be alive. The single option will cause the audit daemon to
162 put the computer system in single user mode. halt option will
163 cause the audit daemon to shutdown the computer system.
164 disk_error_action
166 This parameter tells the system what action to take whenever
167 there is an error detected when writing audit events to disk or
168 rotating logs. Valid values are ignore, syslog, exec, suspend,
169 single, and halt. If set to ignore, the audit daemon does noth‐
170 ing. Syslog means that it will issue a warning to syslog. exec
171 /path-to-script will execute the script. You cannot pass parame‐
172 ters to the script. Suspend will cause the audit daemon to stop
173 writing records to the disk. The daemon will still be alive. The
174 single option will cause the audit daemon to put the computer
175 system in single user mode. halt option will cause the audit
176 daemon to shutdown the computer system.
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180 In a CAPP environment, the audit trail is considered so important that
181 access to system resources must be denied if an audit trail cannot be
182 created. In this environment, it would be suggested that /var/log/audit
183 be on its own partition. This is to ensure that space detection is
184 accurate and that no other process comes along and consumes part of it.
185 The flush parameter should be set to sync or data.
187 Max_log_file and num_logs need to be adjusted so that you get complete
189 use of your partition. It should be noted that the more files that have
190 to be rotated, the longer it takes to get back to receiving audit
191 events. Max_log_file_action should be set to keep_logs.
192 Space_left should be set to a number that gives the admin enough time
194 to react to any alert message and perform some maintenance to free up
195 disk space. This would typically involve running the aureport -t report
196 and moving the oldest logs to an archive area. The value of space_left
197 is site dependant since the rate at which events are generated varies
198 with each deployment. The space_left_action is recommended to be set to
199 email. If you need something like an snmp trap, you can use the exec
200 option to send one.
201 Admin_space_left should be set to the amount of disk space on the audit
203 partition needed for admin actions to be recorded.
204 Admin_space_left_action would be set to single so that use of the
205 machine is restricted to just the console.
206 The disk_full_action is triggered when no more room exists on the par‐
208 tition. All access should be terminated since no more audit capability
209 exists. This can be set to either single or halt.
210 The disk_error_action should be set to syslog, single, or halt depend‐
212 ing on your local policies regarding handling of hardware malfunctions.
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216 /etc/audit/auditd.conf
217 Audit daemon configuration file
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221 auditd(8).
222
225 Steve Grubb
226Red Hat Aug 2007 AUDITD.CONF:(5)