SELinux/audit2allow

AUDIT2ALLOW(1)                        NSA                       AUDIT2ALLOW(1)

NAME
audit2allow  -  generate  policy allow rules from logs of denied opera-
tions

SYNOPSIS
audit2allow [options] 

OPTIONS
-a | --all
Read input from audit and message log, conflicts with -i

-d | --dmesg
Read input from output of /bin/dmesg.  Note that all audit  mes-
sages  are  not  available via dmesg when auditd is running; use
"ausearch -m avc | audit2allow"  or "-a" instead.

-f | --fcfile <File Context File>
Add File Context File to generated Module Package.  Requires  -M
option.

-h | --help
Print a short usage message

-i  <inputfile> | --input <inputfile>
read input from <inputfile>

-l | --lastreload
read input only after last policy reload

-m <modulename> | --module <modulename>
Generate module/require output <modulename>

-M <modulename>
Generate loadable module package, conflicts with -o

-o <outputfile> | --output <outputfile>
append output to <outputfile>

-r | --requires
Generate require output syntax for loadable modules.

-t  | --tefile
Indicates  input file is a te (type enforcement) file.  This can
be used to translate old te format to new policy format.

-v | --verbose
Turn on verbose output

DESCRIPTION
This utility scans the logs for messages logged when the system  denied
permission  for  operations,  and  generates  a snippet of policy rules
which, if loaded into policy, might have allowed  those  operations  to
succeed.  However,  this  utility  only generates Type Enforcement (TE)
allow rules.  Certain permission denials may  require  other  kinds  of
policy  changes, e.g. adding an attribute to a type declaration to sat-
isfy an existing constraint, adding a role allow rule, or  modifying  a
constraint.   The audit2why(8) utility may be used to diagnose the rea-
son when it is unclear.

Care must be exercised while acting on the output of  this  utility  to
ensure  that  the  operations  being  permitted  do not pose a security
threat. Often it is better to define new domains and/or types, or  make
other structural changes to narrowly allow an optimal set of operations
to succeed, as opposed to  blindly  implementing  the  sometimes  broad
changes  recommended  by this utility.   Certain permission denials are
not fatal to the application, in which case it  may  be  preferable  to
simply  suppress  logging  of  the denial via a dontaudit rule rather
than an allow rule.

EXAMPLE
Using audit2allow to generate monolithic (non-module) policy
$ cd /etc/selinux/$SELINUXTYPE/src/policy
$ cat /var/log/audit/audit.log | audit2allow >> domains/misc/local.te
$ cat domains/misc/local.te
allow cupsd_config_t unconfined_t:fifo_file { getattr ioctl };
<review domains/misc/local.te and customize as desired>
$ make load

Using audit2allow to generate module policy

$ cat /var/log/audit/audit.log | audit2allow -m local > local.te
$ cat local.te
module local 1.0;

require {
role system_r;

class fifo_file {  getattr ioctl };

type cupsd_config_t;
type unconfined_t;
};

allow cupsd_config_t unconfined_t:fifo_file { getattr ioctl };
<review local.te and customize as desired>

Building module policy manually

$ checkmodule -M -m -o local.mod local.te
$ semodule_package -o local.pp -m local.mod
$ semodule -i local.pp

Using audit2allow to generate and build module policy
$ cat /var/log/audit/audit.log | audit2allow -M local
Generating type enforcment file: local.te
Compiling policy: checkmodule -M -m -o local.mod local.te
Building package: semodule_package -o local.pp -m local.mod

******************** IMPORTANT ***********************

In order to load this newly created policy package into the kernel,
you are required to execute

semodule -i local.pp

AUTHOR
This manual page was written by Manoj Srivastava <srivasta@debian.org>,
for   the  Debian  GNU/Linux  system.  It  was  updated  by  Dan  Walsh
<dwalsh@redhat.com>

The audit2allow utility has contributions from several people,  includ-
ing Justin R. Smith and Yuichi Nakamura.  and Dan Walsh

Security Enhanced Linux          January 2005                   AUDIT2ALLOW(1)