SELinux : audit2allow Basic Usage2019/09/28 |
Using [audit2allow] command, it's possible to generate SELinux policy allow rules easily from logs of denied operations.
However, [audit2allow] may allow more access than required, so it's better to configure with
[restorecon] or [chcon] command in cases.
By the way, if [audit2allow] is none on your System, Install with [dnf install policycoreutils-python-utils].
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[1] | Display denial reasons to read log files. If not specified any log file, audit2allow reads [/var/log/audit/audit.log]. If specify log files, set [-i logfile] option instead [-a] option. |
# display reason for AVC denials from reading audit.log [root@dlp ~]# audit2allow -w -a type=AVC msg=audit(1569562236.212:158): avc: denied { name_bind } for pid=28610 comm="httpd" src=83 scontext=system_u:system_r:httpd_t:s0 tcontext=system_u:object_r:reserved_port_t:s0 tclass=tcp_socket permissive=0 Was caused by: Missing type enforcement (TE) allow rule. You can use audit2allow to generate a loadable module to allow this access. ..... ..... type=AVC msg=audit(1569653763.280:73): avc: denied { getattr } for pid=1378 comm="httpd" path="/var/www/html/cgi-enabled/index.py" dev="dm-0" ino=460792 scontext=system_u:system_r:httpd_t:s0 tcontext=unconfined_u:object_r:user_home_dir_t:s0 tclass=file permissive=0 Was caused by: Missing type enforcement (TE) allow rule. You can use audit2allow to generate a loadable module to allow this access. # for example, use ausearch to display specific logs [root@dlp ~]# ausearch -m AVC --start 09/28/2019 12:00:00 --end 09/28/2019 18:00:00 | audit2allow -w type=AVC msg=audit(1569653763.279:72): avc: denied { getattr } for pid=1378 comm="httpd" path="/var/www/html/cgi-enabled/index.py" dev="dm-0" ino=460792 scontext=system_u:system_r:httpd_t:s0 tcontext=unconfined_u:object_r:user_home_dir_t:s0 tclass=file permissive=0 Was caused by: Missing type enforcement (TE) allow rule. You can use audit2allow to generate a loadable module to allow this access. type=AVC msg=audit(1569653763.280:73): avc: denied { getattr } for pid=1378 comm="httpd" path="/var/www/html/cgi-enabled/index.py" dev="dm-0" ino=460792 scontext=system_u:system_r:httpd_t:s0 tcontext=unconfined_u:object_r:user_home_dir_t:s0 tclass=file permissive=0 Was caused by: Missing type enforcement (TE) allow rule. You can use audit2allow to generate a loadable module to allow this access. # display required type with -a option [root@dlp ~]# ausearch -m AVC --start 09/28/2019 12:00:00 --end 09/28/2019 18:00:00 | audit2allow -a #============= httpd_t ============== allow httpd_t user_home_dir_t:file getattr; |
[2] | Generate allow rule like follows. |
# for example, generate [test_rule] module [root@dlp ~]# ausearch -m AVC --start 09/28/2019 12:00:00 --end 09/28/2019 18:00:00 | audit2allow -a -M test_rule ******************** IMPORTANT *********************** To make this policy package active, execute: semodule -i test_rule.pp # install module with the command displayed above [root@dlp ~]# semodule -i test_rule.pp
# make sure the module is loaded [root@dlp ~]# semodule -l | grep test_rule test_rule |
[3] | That's OK in some cases, but for other cases, it's not yet. If not yet, run [audit2allow] again and make sure the causes. |
[root@dlp ~]# curl localhost/cgi-enabled/index.py CGI Test Page |
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