.\" Hey, Emacs! This is an -*- nroff -*- source file. .\" Copyright (c) 2005 Manoj Srivastava .\" .\" This is free documentation; you can redistribute it and/or .\" modify it under the terms of the GNU General Public License as .\" published by the Free Software Foundation; either version 2 of .\" the License, or (at your option) any later version. .\" .\" The GNU General Public License's references to "object code" .\" and "executables" are to be interpreted as the output of any .\" document formatting or typesetting system, including .\" intermediate and printed output. .\" .\" This manual is distributed in the hope that it will be useful, .\" but WITHOUT ANY WARRANTY; without even the implied warranty of .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the .\" GNU General Public License for more details. .\" .\" You should have received a copy of the GNU General Public .\" License along with this manual; if not, write to the Free .\" Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, .\" USA. .\" .\" .TH AUDIT2ALLOW "1" "January 2005" "Security Enhanced Linux" NSA .SH NAME .BR audit2allow \- generate SELinux policy allow rules from logs of denied operations .BR audit2why \- translates SELinux audit messages into a description of why the access was denied (audit2allow -w) .SH SYNOPSIS .B audit2allow .RI [ options "] " .SH OPTIONS .TP .B "\-a" | "\-\-all" Read input from audit and message log, conflicts with -i .TP .B "\-d" | "\-\-dmesg" Read input from output of .I /bin/dmesg. Note that all audit messages are not available via dmesg when auditd is running; use "ausearch -m avc | audit2allow" or "-a" instead. .TP .B "\-f" | "\-\-fcfile" Add File Context File to generated Module Package. Requires -M option. .TP .B "\-h" | "\-\-help" Print a short usage message .TP .B "\-i " | "\-\-input " read input from .I .TP .B "\-l" | "\-\-lastreload" read input only after last policy reload .TP .B "\-m " | "\-\-module " Generate module/require output .TP .B "\-M " Generate loadable module package, conflicts with -o .TP .B "\-o " | "\-\-output " append output to .I .TP .B "\-r" | "\-\-requires" Generate require output syntax for loadable modules. .TP .B "\-N" | "\-\-noreference" Do not generate reference policy, traditional style allow rules. This is the default behavior. .TP .B "\-R" | "\-\-reference" Generate reference policy using installed macros. This attempts to match denials against interfaces and may be inaccurate. .TP .B "\-t " | "\-\-tefile" Indicates input file is a te (type enforcement) file. This can be used to translate old te format to new policy format. .TP .B "\-w" | "\-\-why" Translates SELinux audit messages into a description of why the access wasn denied .TP .B "\-v" | "\-\-verbose" Turn on verbose output .SH DESCRIPTION .PP 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 .BR audit2why (8) utility may be used to diagnose the reason when it is unclear. .PP 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. .PP .SH EXAMPLE .nf .B NOTE: These examples are for systems using the audit package. If you do .B not use the audit package, the AVC messages will be in /var/log/messages. .B Please substitute /var/log/messages for /var/log/audit/audit.log in the .B examples. .PP .B 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 .B 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 }; .B 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 .B 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 .fi .PP .SH AUTHOR This manual page was written by .I Manoj Srivastava , for the Debian GNU/Linux system. It was updated by Dan Walsh .PP The .B audit2allow utility has contributions from several people, including .I Justin R. Smith and .I Yuichi Nakamura. and .I Dan Walsh