SELinux : Use SETroubleShoot2016/04/05 |
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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. |
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[root@dlp ~]#
yum -y install setroubleshoot-server
[root@dlp ~]#
vi /etc/tmpfiles.d/setroubleshoot.conf # create new D /var/run/setroubleshoot 0755 setroubleshoot root - mkdir --context=system_u:object_r:setroubleshoot_var_run_t:s0 /var/run/setroubleshoot [root@dlp ~]# chown setroubleshoot:root /var/run/setroubleshoot [root@dlp ~]# chmod 755 /var/run/setroubleshoot [root@dlp ~]# service auditd restart [root@dlp ~]# systemctl restart dbus |
| [3] | It's OK all, additional logs for AVC denial are output to /var/log/messages like follows. |
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[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
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| [4] | For 4the line on the example above, a command is given to see more details and it displays logs like follows. |
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[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
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