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NAME | SYNOPSIS | OPTIONS | DESCRIPTION | EXAMPLE | AUTHOR | COLOPHON |
AUDIT2ALLOW(1) NSA AUDIT2ALLOW(1)
audit2allow - generate SELinux policy allow/dontaudit rules from logs
of denied operations
audit2why - translates SELinux audit messages into a description of
why the access was denied (audit2allow -w)
audit2allow [options]
-a | --all
Read input from audit and message log, conflicts with -i
-b | --boot
Read input from audit messages since last boot 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.
-D | --dontaudit
Generate dontaudit rules (Default: allow)
-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
-p <policyfile> | --policy <policyfile>
Policy file to use for analysis
-o <outputfile> | --output <outputfile>
append output to <outputfile>
-r | --requires
Generate require output syntax for loadable modules.
-N | --noreference
Do not generate reference policy, traditional style allow
rules. This is the default behavior.
-R | --reference
Generate reference policy using installed macros. This
attempts to match denials against interfaces and may be
inaccurate.
-w | --why
Translates SELinux audit messages into a description of why
the access was denied
-v | --verbose
Turn on verbose output
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.
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 module policy
$ cat /var/log/audit/audit.log | audit2allow -m local > local.te
$ cat local.te
module local 1.0;
require {
class file { getattr open read };
type myapp_t;
type etc_t;
};
allow myapp_t etc_t:file { getattr open read };
<review local.te and customize as desired>
Using audit2allow to generate module policy using reference policy
$ cat /var/log/audit/audit.log | audit2allow -R -m local > local.te
$ cat local.te
policy_module(local, 1.0)
gen_require(`
type myapp_t;
type etc_t;
};
files_read_etc_files(myapp_t)
<review local.te and customize as desired>
Building module policy using Makefile
# SELinux provides a policy devel environment under
# /usr/share/selinux/devel including all of the shipped
# interface files.
# You can create a te file and compile it by executing
$ make -f /usr/share/selinux/devel/Makefile local.pp
# This make command will compile a local.te file in the current
# directory. If you did not specify a "pp" file, the make file
# will compile all "te" files in the current directory. After
# you compile your te file into a "pp" file, you need to install
# it using the semodule command.
$ semodule -i local.pp
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 enforcement 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
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
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
This page is part of the selinux (Security-Enhanced Linux user-space
libraries and tools) project. Information about the project can be
found at ⟨https://github.com/SELinuxProject/selinux/wiki⟩. If you
have a bug report for this manual page, see
⟨https://github.com/SELinuxProject/selinux/wiki/Contributing⟩. This
page was obtained from the project's upstream Git repository
⟨https://github.com/SELinuxProject/selinux⟩ on 2017-07-05. If you
discover any rendering problems in this HTML version of the page, or
you believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
Security Enhanced Linux October 2010 AUDIT2ALLOW(1)