SELinux : Use SETroubleShoot
2016/07/26 |
To use SETroubleShoot, it's possible to generate additional logs for solving some troubles.
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[1] |
Messages from SETroubleShoot are sent by Audit Event Dispatcher to /var/log/messages.
So it needs to run Auditd, refer to here. |
[2] | Install setroubleshoot-server. And Configure some settings for using sealert command. |
[root@dlp ~]#
[root@dlp ~]# yum -y install setroubleshoot-server service auditd restart [root@dlp ~]# service messagebus restart |
[3] | It's OK all, additional logs for AVC denial are output to /var/log/messages like follows. |
[root@dlp ~]# grep -E 'setroubleshoot|preventing' /var/log/messages Apr 3 19:33:41 dlp setroubleshoot: failed to retrieve rpm info for /var/www/html/index.html Apr 3 19:33:41 dlp setroubleshoot: SELinux is preventing /usr/sbin/httpd from getattr access on the file /var/www/html/index.html. For complete SELinux messages. run sealert -l 84495686-3c5c-411f-9fb7-bb396ac49c1d Apr 3 19:33:41 dlp python: SELinux is preventing /usr/sbin/httpd from getattr access on the file /var/www/html/index.html. #012#012***** Plugin restorecon (99.5 confidence) suggests ************************#012#012 If you want to fix the label. #012/var/www/html/index.html default label should be httpd_sys_content_t. #012Then you can run restorecon.#012Do#012# /sbin/restorecon -v /var/www/html/index.html#012#012***** Plugin catchall (1.49 confidence) suggests **************************#012#012If you believe that httpd should be allowed getattr access on the index.html file by default.#012Then you should report this as a bug.#012You can generate a local policy module to allow this access.#012Do#012allow this access for now by executing:#012# grep httpd /var/log/audit/audit.log | audit2allow -M mypol#012# semodule -i mypol.pp#012 |
[4] | For 4the line on the example above, a command is given to see more details and it displays logs like follows. |
[root@dlp ~]# sealert -l 84495686-3c5c-411f-9fb7-bb396ac49c1d SELinux is preventing /usr/sbin/httpd from getattr access on the file /var/www/html/index.html. ***** Plugin restorecon (99.5 confidence) suggests ************************ If you want to fix the label. /var/www/html/index.html default label should be httpd_sys_content_t. Then you can run restorecon. Do # /sbin/restorecon -v /var/www/html/index.html ***** Plugin catchall (1.49 confidence) suggests ************************** If you believe that httpd should be allowed getattr access on the index.html file by default. Then you should report this as a bug. You can generate a local policy module to allow this access. Do allow this access for now by executing: # grep httpd /var/log/audit/audit.log | audit2allow -M mypol # semodule -i mypol.pp Additional Information: Source Context system_u:system_r:httpd_t:s0 Target Context unconfined_u:object_r:admin_home_t:s0 Target Objects /var/www/html/index.html [ file ] Source httpd Source Path /usr/sbin/httpd Port <Unknown> Host dlp.srv.world Source RPM Packages httpd-2.4.6-40.el7.centos.x86_64 Target RPM Packages Policy RPM selinux-policy-3.13.1-60.el7_2.3.noarch Selinux Enabled True Policy Type targeted Enforcing Mode Enforcing Host Name dlp.srv.world Platform Linux dlp.srv.world 3.10.0-327.10.1.el7.x86_64 #1 SMP Tue Feb 16 17:03:50 UTC 2016 x86_64 x86_64 Alert Count 3 First Seen 2016-04-03 19:11:23 JST Last Seen 2016-04-03 19:33:40 JST Local ID 84495686-3c5c-411f-9fb7-bb396ac49c1d Raw Audit Messages type=AVC msg=audit(1459845220.621:57): avc: denied { getattr } for pid=847 comm="httpd" path="/var/www/html/index.html" dev="dm-0" ino=101186198 scontext=system_u:system_r:httpd_t:s0 tcontext=unconfined_u:object_r:admin_home_t:s0 tclass=file type=SYSCALL msg=audit(1459845220.621:57): arch=x86_64 syscall=lstat success=no exit=EACCES a0=7fb4dab46f70 a1=7fff43babe90 a2=7fff43babe90 a3=0 items=0 ppid=822 pid=847 auid=4294967295 uid=48 gid=48 euid=48 suid=48 fsuid=48 egid=48 sgid=48 fsgid=48 tty=(none) ses=4294967295 comm=httpd exe=/usr/sbin/httpd subj=system_u:system_r:httpd_t:s0 key=(null) Hash: httpd,httpd_t,admin_home_t,file,getattr |