Manual Reference Pages  - AUDIT2ALLOW (1)

NAME

audit2allow - generate SELinux policy allow rules from logs of denied operations

CONTENTS

Synopsis
Options
Description
Example
Author

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 messages are not available via dmesg when auditd is running; use "ausearch -m avc | audit2allow" or "-a" instead.
-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.
-R | --reference
  Generate reference policy using installed macros. Requires the selinux-policy-devel package.
-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 satisfy an existing constraint, adding a role allow rule, or modifying a constraint. The audit2why(8) utility may be used to diagnose the reason 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


NOTE: These examples are for systems using the audit package. If you do 

not use the audit package, the AVC messages will be in /var/log/messages. 

Please substitute /var/log/messages for /var/log/audit/audit.log in the 

examples. 

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

# Compile the module $ checkmodule -M -m -o local.mod local.te # Create the package $ semodule_package -o local.pp -m local.mod # Load the module into the kernel $ 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, including Justin R. Smith and Yuichi Nakamura. and Dan Walsh


Security Enhanced Linux AUDIT2ALLOW (1) January 2005
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