Proprietary telnet daemon fails login when SELinux is enabled

[Dave Stoner]

I apologise in advance for asking questions which I feel I should have
been able to answer from sources on the internet. If you could possibly
give me some pointers on where to look it would be so much appreciated.

 

My system is centos 6.2 - 

Linux MyHostName 2.6.32-220.el6.x86_64 #1 SMP Tue Dec 6 19:48:22

GMT 2011 x86_64 x86_64 x86_64 GNU/Linux

 

SELinux mode is set 'enforced'.

 

I have a proprietary telnet daemon which upon a telnet to port 52000, is
started OK when SELinux is disabled. But when it is enabled the same
telnet results in /var/log/audit/audit.log showing:

 

type=USER_LOGIN msg=audit(1343048458.345:69): user pid=2536 uid=0
auid=799 ses=7 subj=system_u:system_r:inetd_t:s0-s0:c0.c1023
msg='op=login id=799 exe="/bin/login" hostname=0.0.0.0 addr=0.0.0.0
termi

nal=pts/2 res=success'

 

A normal telnet gives a message similar to above, my telnet adds the
following:

 

type=AVC msg=audit(1343048458.353:70): avc:  denied  { entrypoint } for
pid=2543 comm="login" path="/bin/bash" dev=sda2 ino=135083
scontext=unconfined_u:system_r:qmail_tcp_env_t:s0-s0:c0.c1023 tconte

xt=system_u:object_r:shell_exec_t:s0 tclass=file

 

I believe I can create a policy to overcome this using audit2allow, i.e.
it comes up with:

 

module mypola 1.0;

 

require {

        type qmail_tcp_env_t;

        type shell_exec_t;

        class file entrypoint;

}

 

#============= qmail_tcp_env_t ==============

allow qmail_tcp_env_t shell_exec_t:file entrypoint;

 

But it seems to me what I ought to be doing is somehow to get my daemon
to run with a domain of 'remote_logon_t' as is used by the standard
telnet daemon, as here:

 

type=USER_LOGIN msg=audit(1343058924.928:212): user pid=3759 uid=0
auid=799 ses=29 subj=system_u:system_r:remote_login_t:s0-s0:c0.c1023
msg='op=login id=799 exe="/bin/login" hostname=localhost addr=::

1 terminal=pts/2 res=success'

 

This is unfamiliar territory and any hints or pointers would really be
appreciated.

 

Dave.

 

 

Dave Stoner

Principal Systems Architect
Northgate Reality

Direct:    [phone] - VPN: 872 2071

www.northgate-is.com/reality <http://www.northgate-is.com/reality>  

 


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