huschi.net

AUDIT2ALLOW(1)                        NSA                       AUDIT2ALLOW(1)
NAME
       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)
SYNOPSIS
       audit2allow [options]
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 mes-
              sages 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.
       -x | --xperms
              Generate extended permission access vector rules
       -w | --why
              Translates  SELinux audit messages into a description of why the
              access was denied
       -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 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
AUTHOR
       This manual page was written by Manoj Srivastava <srivasta AT debian.org>,
       for   the  Debian  GNU/Linux  system.  It  was  updated  by  Dan  Walsh
       <dwalsh AT redhat.com>
       The audit2allow utility has contributions from several people,  includ-
       ing Justin R. Smith and Yuichi Nakamura.  and Dan Walsh
Security Enhanced Linux          October 2010                   AUDIT2ALLOW(1)