AUDIT2ALLOW(1) NSA AUDIT2ALLOW(1)NAMEaudit2allow - generate SELinux policy allow rules from logs of denied
operations
SYNOPSISaudit2allow [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.
-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 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
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, includ‐
ing Justin R. Smith and Yuichi Nakamura. and Dan Walsh
Security Enhanced Linux January 2005 AUDIT2ALLOW(1)
