SELinux — описание и особенности работы с системой. Часть 2

Индивидуальная настройка политик SELinux

# getsebool -a

# setsebool -P httpd_can_network_connect on

Создание пользовательских политик при помощи audit2allow

type=AVC msg=audit(1218128130.653:334): avc: denied { connectto } for pid=9111 comm="smtpd" path="/var/spool/postfix/postgrey/socket"
scontext=system_u:system_r:postfix_smtpd_t:s0 tcontext=system_u:system_r:initrc_t:s0 tclass=unix_stream_socket
type=AVC msg=audit(1218128130.653:334): avc: denied { write } for pid=9111 comm="smtpd" name="socket" dev=sda6 ino=39977017
scontext=system_u:system_r:postfix_smtpd_t:s0 tcontext=system_u:object_r:postfix_spool_t:s0 tclass=sock_file 

# grep smtpd_t /var/log/audit/audit.log | audit2allow -m postgreylocal > postgreylocal.te
# cat postgreylocal.te
module postgreylocal 1.0;
require {
 type postfix_smtpd_t;
 type postfix_spool_t;
 type initrc_t;
 class sock_file write;
 class unix_stream_socket connectto;
}
#============= postfix_smtpd_t ==============
allow postfix_smtpd_t initrc_t:unix_stream_socket connectto;
allow postfix_smtpd_t postfix_spool_t:sock_file write; 

# grep smtpd_t /var/log/audit/audit.log | audit2allow -M postgreylocal 

# semodule -i postgreylocal.pp 

Ручная настройка модулей для политик SELinux.

Summary:

SELinux is preventing postdrop (postfix_postdrop_t) "getattr" to
/var/log/httpd/error_log (httpd_log_t).

Detailed Description:
SELinux denied access requested by postdrop. It is not expected that this access
is required by postdrop and this access may signal an intrusion attempt. It is
also possible that the specific version or configuration of the application is
causing it to require additional access.
Allowing Access:
Sometimes labeling problems can cause SELinux denials. You could try to restore
the default system file context for /var/log/httpd/error_log,
restorecon -v '/var/log/httpd/error_log'
If this does not work, there is currently no automatic way to allow this access.
Instead, you can generate a local policy module to allow this access - see FAQ
(http://fedora.redhat.com/docs/selinux-faq-fc5/#id2961385) Or you can disable
SELinux protection altogether. Disabling SELinux protection is not recommended.
Please file a bug report (http://bugzilla.redhat.com/bugzilla/enter_bug.cgi)
against this package.

Additional Information:
Source Context system_u:system_r:postfix_postdrop_t
Target Context root:object_r:httpd_log_t
Target Objects /var/log/httpd/error_log [ file ]
Source postdrop
Source Path /usr/sbin/postdrop
Port <Unknown>
Host sanitized
Source RPM Packages postfix-2.3.3-2
Target RPM Packages
Policy RPM selinux-policy-2.4.6-137.1.el5
Selinux Enabled True
Policy Type targeted
MLS Enabled True
Enforcing Mode Enforcing
Plugin Name catchall_file
Host Name sanitized
Platform Linux sanitized 2.6.18-53.1.21.el5 #1 SMP Tue
 May 20 09:35:07 EDT 2008 x86_64 x86_64
Alert Count 599
First Seen Wed Jul 2 08:27:15 2008
Last Seen Sun Aug 10 22:47:52 2008
Local ID c303a4ea-8e7a-4acc-9118-9cc61c6a2ec8
Line Numbers

Raw Audit Messages

host=sanitized type=AVC msg=audit(1218397672.372:352): avc: denied { getattr } for pid=4262 comm="postdrop"
path="/var/log/httpd/error_log" dev=md2 ino=117005 scontext=system_u:system_r:postfix_postdrop_t:s0
tcontext=root:object_r:httpd_log_t:s0 tclass=file
host=sanitized type=SYSCALL msg=audit(1218397672.372:352): arch=c000003e syscall=5 success=no exit=-13 a0=2
a1=7fffd6febca0 a2=7fffd6febca0 a3=0 items=0 ppid=4261 pid=4262 auid=4294967295 uid=48 gid=48 euid=48 suid=48
fsuid=48 egid=90 sgid=90 fsgid=90 tty=(none) comm="postdrop" exe="/usr/sbin/postdrop"
subj=system_u:system_r:postfix_postdrop_t:s0 key=(null) 

# grep postdrop /var/log/audit/audit.log | audit2allow -M postfixlocal
# cat postfixlocal.te
 module postfixlocal 1.0;
 require {
 type httpd_log_t;
 type postfix_postdrop_t;
 class dir getattr;
 class file { read getattr };
 }
 #============= postfix_postdrop_t ==============
 allow postfix_postdrop_t httpd_log_t:file getattr; 

#============= postfix_postdrop_t ==============
dontaudit postfix_postdrop_t httpd_log_t:file getattr;

# checkmodule -M -m -o postfixlocal.mod postfixlocal.te
# semodule_package -o postfixlocal.pp -m postfixlocal.mod
# semodule -i postfixlocal.pp