[CentOS] SELinux and access across 'similar types'

Daniel J Walsh dwalsh at redhat.com
Fri Jan 6 15:13:41 UTC 2012


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On 01/06/2012 09:57 AM, Bennett Haselton wrote:
> On 1/6/2012 5:55 AM, RILINDO FOSTER wrote:
>> On Jan 6, 2012, at 7:40 AM, Philippe Naudin wrote:
>> 
>>> Le ven 06 jan 2012 04:21:14 CET, Bennett Haselton a écrit:
>>> 
>>>> On 1/6/2012 4:11 AM, Philippe Naudin wrote:
>>>>> Le ven 06 jan 2012 02:41:02 CET, Bennett Haselton a écrit:
>>>>> 
>>>>>> On 1/6/2012 2:24 AM, Philippe Naudin wrote:
>>>>>>> Apache running as "init_t" is a call for troubles.
>>>>>> Is it?  OK, any idea what caused that and how to fix it?
>>>>> No, sorry. Your httpd comes from CentOS ?
>>>> Yes
>>>>> Afaik, you should not have any process running in context
>>>>> init_t except init itself. If "ps awuxZ | grep [i]nit_t"
>>>>> returns more than only init and httpd, your problem is
>>>>> likely to be more complicated than a broken configuration
>>>>> of apache.
>>>> I've got a few...
>>>> 
>>>> [root at g6950-21025 ~]# ps auwxZ | grep init_t 
>>>> system_u:system_r:init_t        root         1  0.6  0.0
>>>> 10368   712 ?        Ss   04:17   0:00 init [3]
>>>> 
>>>> system_u:system_r:init_t        root       537  0.2  0.1
>>>> 13728  1976 ?        S<s  04:17   0:00 /sbin/udevd -d 
>>>> system_u:system_r:init_t        root      1684  0.0  0.0
>>>> 38880   456 ?        Ssl  04:18   0:00 brcm_iscsiuio 
>>>> system_u:system_r:init_t        root      1690  0.0  0.0
>>>> 12152   476 ?        Ss   04:18   0:00 iscsid 
>>>> system_u:system_r:init_t        root      1691  0.0  0.4
>>>> 12648  4460 ?        S<Ls 04:18   0:00 iscsid 
>>>> system_u:system_r:init_t        dbus      2081  0.0  0.1
>>>> 31520  1144 ?        Ssl  04:18   0:00 dbus-daemon --system 
>>>> system_u:system_r:init_t        root      2215  0.0  0.1
>>>> 52372  1492 ?        Ssl  04:18   0:00 automount 
>>>> system_u:system_r:init_t        root      2254  0.0  0.1
>>>> 62656  1212 ?        Ss   04:18   0:00 /usr/sbin/sshd 
>>>> system_u:system_r:init_t        ntp       2273  0.0  0.4
>>>> 23412  5044 ?        SLs  04:18   0:00 ntpd -u ntp:ntp -p
>>>> /var /run/ntpd.pid -g system_u:system_r:init_t        root
>>>> 2287  0.1  1.0 253312 10580 ?        Ss   04:18   0:00
>>>> /usr/sbin/httpd system_u:system_r:init_t        apache
>>>> 2315  0.3  1.3 259488 13376 ?        S    04:18   0:00
>>>> /usr/sbin/httpd system_u:system_r:init_t        apache
>>>> 2316  0.0  1.0 257436 11124 ?        S    04:18   0:00
>>>> /usr/sbin/httpd system_u:system_r:init_t        apache
>>>> 2317  0.1  1.1 257436 11288 ?        S    04:18   0:00
>>>> /usr/sbin/httpd system_u:system_r:init_t        apache
>>>> 2318  0.1  1.1 257436 11292 ?        S    04:18   0:00
>>>> /usr/sbin/httpd system_u:system_r:init_t        apache
>>>> 2319  0.0  1.0 256720 10504 ?        S    04:18   0:00
>>>> /usr/sbin/httpd system_u:system_r:init_t        apache
>>>> 2320  0.1  1.0 257436 10752 ?        S    04:18   0:00
>>>> /usr/sbin/httpd system_u:system_r:init_t        apache
>>>> 2321  0.0  1.1 257436 11272 ?        S    04:18   0:00
>>>> /usr/sbin/httpd system_u:system_r:init_t        apache
>>>> 2322  0.1  1.1 257436 11356 ?        S    04:18   0:00
>>>> /usr/sbin/httpd system_u:system_r:init_t        root
>>>> 2386  0.0  0.0   3812   492 tty1     Ss+  04:18   0:00
>>>> /sbin/mingetty tty1 system_u:system_r:init_t        root
>>>> 2387  0.0  0.0   3812   488 tty2     Ss+  04:18   0:00
>>>> /sbin/mingetty tty2 system_u:system_r:init_t        root
>>>> 2390  0.0  0.0   3812   488 tty3     Ss+  04:18   0:00
>>>> /sbin/mingetty tty3 system_u:system_r:init_t        root
>>>> 2392  0.0  0.0   3812   492 tty4     Ss+  04:18   0:00
>>>> /sbin/mingetty tty4 system_u:system_r:init_t        root
>>>> 2394  0.0  0.0   3812   488 tty5     Ss+  04:18   0:00
>>>> /sbin/mingetty tty5 system_u:system_r:init_t        root
>>>> 2397  0.0  0.0   3812   488 tty6     Ss+  04:18   0:00
>>>> /sbin/mingetty tty6 system_u:system_r:init_t        apache
>>>> 2405  0.1  1.0 256412 11008 ?        S    04:18   0:00
>>>> /usr/sbin/httpd system_u:system_r:init_t        root
>>>> 2406  0.3  0.3  90156  3456 ?        Ss   04:18   0:00 sshd:
>>>> root at pts/0 root:system_r:initrc_t:SystemLow-SystemHigh root
>>>> 2458 0.0  0.0 61176 768 pts/0 S+   04:18   0:00 grep init_t
>>>> 
>>>> 
>>>> 
>>>> I also found at least one file (the audit.log file) which has
>>>> file type file_t, even though I thought the filesystem had
>>>> been re-labeled successfully because /var/www/html/robots.txt
>>>> had the correct type:
>>>> 
>>>> [root at g6950-21025 ~]# ls -lZ /var/www/html/robots.txt 
>>>> -rw-rw-rw-  root root system_u:object_r:httpd_sys_content_t 
>>>> /var/www/html/robots.txt [root at g6950-21025 ~]# ls -lZ
>>>> /var/log/audit/audit.log -rw-------  root root
>>>> system_u:object_r:file_t /var/log/audit/audit.log
>>>> 
>>>> 
>>>> Any idea (1) what could be causing that and (2) whether it
>>>> could be related to the problem with all those init_t
>>>> processes?
>>> It's easy : your init process is broken, all these daemons but
>>> init are mis-labeled, so all the files they create (such as log
>>> files) are mis-labeled.
>>> 
>>> And if the next question is "how to fix it ?", the answer is
>>> easy too : "I don't have any clue..."
>>> 
>>> 
>> Assuming that httpd came from CentOS, it should be appropriate
>> relabeled. If not, using the semanage -f context would fix it.
> Are you talking about changing the security context on the 
> /usr/sbin/httpd file itself?  What should it be set to?  Right now
> it's [root at g6950-21025 ~]# ls -lZ /usr/sbin/httpd -rwxr-xr-x  root
> root system_u:object_r:file_t         /usr/sbin/httpd
> 
>> This requires some thought. I'll respond back later.
>> 
> 
> Thanks! _______________________________________________ CentOS
> mailing list CentOS at centos.org 
> http://lists.centos.org/mailman/listinfo/centos

What does

restorecon -R -v /usr/sbin


Say?

If this changes the label, then execute

fixfiles restore

Which should relabel the system.

If restorecon does nothing or prints error messages,

What file system are you using?
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