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  Add File Context File to generated Module Package. Requires -M option.

-h | --help Print a short usage message

-i | --input read input from

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

-m | --module Generate module/require output

-M Generate loadable module package, conflicts with -o

-o | --output append output to

-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 };  $ 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 }; 

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 , for  the  Debian  GNU/Linux  system. It was  updated  by  Dan  Walsh 

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)