From 7f8858f8632d77497765bab79922f1762ce46d50 Mon Sep 17 00:00:00 2001 From: Alexander Bokovoy Date: Tue, 16 Oct 2018 17:54:09 +0300 Subject: [PATCH] net groupmap: force using empty config when mapping Guests When we define a group mapping for BUILTIN\Guests to 'nobody' group in we run 'net groupmap add ...' with a default /etc/samba/smb.conf which is now configured to use ipasam passdb module. We authenticate to LDAP with GSSAPI in ipasam passdb module initialization. If GSSAPI authentication failed (KDC is offline, for example, during server upgrade), 'net groupmap add' crashes after ~10 attempts to re-authenticate. This is intended behavior in smbd/winbindd as they cannot work anymore. However, for the command line tools there are plenty of operations where passdb module is not needed. Additionally, GSSAPI authentication uses the default ccache in the environment and a key from /etc/samba/samba.keytab keytab. This means that if you'd run 'net *' as root, it will replace whatever Kerberos tickets you have with a TGT for cifs/`hostname` and a service ticket to ldap/`hostname` of IPA master. Apply a simple solution to avoid using /etc/samba/smb.conf when we set up the group mapping by specifying '-s /dev/null' in 'net groupmap' call. For upgrade code this is enough as in a678336b8b36cdbea2512e79c09e475fdc249569 we enforce use of empty credentials cache during upgrade to prevent tripping on individual ccaches from KEYRING: or KCM: cache collections. Related: https://pagure.io/freeipa/issue/7705 (cherry picked from commit e48f5a4d64d95c4c5cb5f8ede39cae5c7c1e512c) --- ipaserver/install/adtrustinstance.py | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/ipaserver/install/adtrustinstance.py b/ipaserver/install/adtrustinstance.py index da16748cf..3a751ccb2 100644 --- a/ipaserver/install/adtrustinstance.py +++ b/ipaserver/install/adtrustinstance.py @@ -114,8 +114,8 @@ def make_netbios_name(s): def map_Guests_to_nobody(): env = {'LC_ALL': 'C'} - args = [paths.NET, 'groupmap', 'add', 'sid=S-1-5-32-546', - 'unixgroup=nobody', 'type=builtin'] + args = [paths.NET, '-s', '/dev/null', 'groupmap', 'add', + 'sid=S-1-5-32-546', 'unixgroup=nobody', 'type=builtin'] logger.debug("Map BUILTIN\\Guests to a group 'nobody'") ipautil.run(args, env=env, raiseonerr=False, capture_error=True) -- 2.17.2