Bug 1178116

Summary: Default selinux policy prevents ssh-ldap-helper from connecting to LDAP server
Product: Red Hat Enterprise Linux 7 Reporter: Justin Lambert <jlambert>
Component: opensshAssignee: Jakub Jelen <jjelen>
Status: CLOSED ERRATA QA Contact: Stanislav Zidek <szidek>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.0CC: marianne, mmalik, plautrba, tmraz
Target Milestone: rcKeywords: Documentation, Reopened
Target Release: ---   
Hardware: Unspecified   
OS: Linux   
Whiteboard:
Fixed In Version: openssh-6.6.1p1-13.el7 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2015-11-19 08:02:29 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1191021    

Description Justin Lambert 2015-01-02 12:00:16 UTC
Description of problem:
When using openssh-ldap the default selinux policy prevents connections to the LDAP server.


Version-Release number of selected component (if applicable):
openssh-6.4p1-8.el7.x86_64
openssh-ldap-6.4p1-8.el7.x86_64

How reproducible:
Install and configure openssh-ldap, attempt to SSH to the host.

Steps to Reproduce:
1.
2.
3.

Actual results:
Error in the audit log:
type=AVC msg=audit(1420058593.479:6643): avc:  denied  { name_connect } for  pid=26849 comm="ssh-ldap-helper" dest=389 scontext=system_u:system_r:sshd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:ldap_port_t:s0 tclass=tcp_socket

and LDAP not queried for the public key.

Expected results:
LDAP queried for the public key and result returned

Additional info:
From the setroubleshoot script:

If you believe that ssh-ldap-helper should be allowed name_connect access on the  tcp_socket 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 ssh-ldap-helper /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp

Comment 1 Justin Lambert 2015-01-02 12:05:45 UTC
It looks like this can also be resolved with:
setsebool -P authlogin_nsswitch_use_ldap 1

This is not mentioned in the HOWTO.ldap-keys file, it should be added there.

Comment 3 Milos Malik 2015-01-04 12:51:26 UTC
# rpm -qa selinux-policy\*
selinux-policy-mls-3.12.1-153.el7_0.13.noarch
selinux-policy-minimum-3.12.1-153.el7_0.13.noarch
selinux-policy-3.12.1-153.el7_0.13.noarch
selinux-policy-doc-3.12.1-153.el7_0.13.noarch
selinux-policy-sandbox-3.12.1-153.el7_0.13.noarch
selinux-policy-devel-3.12.1-153.el7_0.13.noarch
selinux-policy-targeted-3.12.1-153.el7_0.13.noarch
# sesearch -s sshd_t -t ldap_port_t -c tcp_socket -p name_connect -A -C
Found 3 semantic av rules:
DT allow nsswitch_domain ldap_port_t : tcp_socket { recv_msg send_msg name_connect } ; [ authlogin_nsswitch_use_ldap ]
ET allow sshd_t reserved_port_type : tcp_socket name_connect ; [ nis_enabled ]
ET allow nsswitch_domain reserved_port_type : tcp_socket name_connect ; [ nis_enabled ]

# 

Usage of authlogin_nsswitch_use_ldap boolean is the right way to go.

Comment 4 Petr Lautrbach 2015-02-17 13:18:36 UTC
$ audit2allow 
type=AVC msg=audit(1420058593.479:6643): avc:  denied  { name_connect } for  pid=26849 comm="ssh-ldap-helper" dest=389 scontext=system_u:system_r:sshd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:ldap_port_t:s0 tclass=tcp_socket


#============= sshd_t ==============

#!!!! This avc can be allowed using one of the these booleans:
#     nis_enabled, authlogin_nsswitch_use_ldap
allow sshd_t ldap_port_t:tcp_socket name_connect;


As it's suggested in comment 3, setting authlogin_nsswitch_use_ldap variable to yes should fix the issue, eg:

# setsebool -P authlogin_nsswitch_use_ldap on

or

# semanage boolean --modify --on authlogin_nsswitch_use_ldap

Comment 5 Justin Lambert 2015-02-17 13:35:17 UTC
Closed without adding anything to the README?  If I had this issue, it seems that someone else will as well.

Comment 6 Petr Lautrbach 2015-02-17 13:37:09 UTC
I missed that, sorry. We'll provide a note in HOWTO.ldap-keys

Comment 8 Jakub Jelen 2015-04-17 14:53:07 UTC
I would be for such addition to HOWTO.ldap-keys:

===============
@@ -51,6 +51,9 @@
   * There are some debug options
   * Example
       /usr/libexec/openssh -s -f /etc/ldap.conf -w -d >> /tmp/ldapdebuglog.txt
+7) Configure SELinux boolean which allows ldap-helper to bind ldap server
+  Run this command
+  # setsebool -P authlogin_nsswitch_use_ldap on
 
 HOW TO MIGRATE FROM LPK
 
===============

Comment 13 errata-xmlrpc 2015-11-19 08:02:29 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2015-2088.html