CentOS7-basierter SSH-Echtzeitcontainer: Das Setup der PAM-Sitzung schlägt fehl

Ich kann mich nicht bei einem SSH-Host anmelden, der in einem auf CentOS7 basierenden rkt-Container ausgeführt wird, da das Setup der PAM-Sitzung niemals abgeschlossen wird. Selbst wenn die Protokollierung auf DEBUG3 eingestellt ist, wird keine Fehlermeldung angezeigt. Die Protokolle enden nur mit sshd[10]: debug3: PAM: opening sessionder Client-Seite Write failed: Broken pipe. Der SSH-Daemon läuft weiter.

/etc/ssh/sshd_config:

# $OpenBSD: sshd_config,v 1.93 2014/01/10 05:59:19 djm Exp $  # This is the sshd server system-wide configuration file. See # sshd_config(5) for more information.  # This sshd was compiled with PATH=/usr/local/bin:/usr/bin  # The strategy used for options in the default sshd_config shipped with # OpenSSH is to specify options with their default value where # possible, but leave them commented. Uncommented options override the # default value.  # If you want to change the port on a SELinux system, you have to tell # SELinux about this change. # semanage port -a -t ssh_port_t -p tcp #PORTNUMBER # #Port 22 #AddressFamily any #ListenAddress 0.0.0.0 #ListenAddress ::  # The default requires explicit activation of protocol 1 #Protocol 2  # HostKey for protocol version 1 #HostKey /etc/ssh/ssh_host_key # HostKeys for protocol version 2 HostKey /etc/ssh/ssh_host_rsa_key #HostKey /etc/ssh/ssh_host_dsa_key HostKey /etc/ssh/ssh_host_ecdsa_key HostKey /etc/ssh/ssh_host_ed25519_key  # Lifetime and size of ephemeral version 1 server key #KeyRegenerationInterval 1h #ServerKeyBits 1024  # Ciphers and keying #RekeyLimit default none  # Logging # obsoletes QuietMode and FascistLogging #SyslogFacility AUTH SyslogFacility AUTHPRIV LogLevel DEBUG3  # Authentication:  #LoginGraceTime 2m #PermitRootLogin yes #StrictModes yes #MaxAuthTries 6 #MaxSessions 10  #RSAAuthentication yes #PubkeyAuthentication yes  # The default is to check both .ssh/authorized_keys and .ssh/authorized_keys2 # but this is overridden so installations will only check .ssh/authorized_keys AuthorizedKeysFile .ssh/authorized_keys  #AuthorizedPrincipalsFile none  #AuthorizedKeysCommand none #AuthorizedKeysCommandUser nobody  # For this to work you will also need host keys in /etc/ssh/ssh_known_hosts #RhostsRSAAuthentication no # similar for protocol version 2 #HostbasedAuthentication no # Change to yes if you don't trust ~/.ssh/known_hosts for # RhostsRSAAuthentication and HostbasedAuthentication #IgnoreUserKnownHosts no # Don't read the user's ~/.rhosts and ~/.shosts files #IgnoreRhosts yes  # To disable tunneled clear text passwords, change to no here! #PasswordAuthentication yes #PermitEmptyPasswords no PasswordAuthentication yes  # Change to no to disable s/key passwords #ChallengeResponseAuthentication yes ChallengeResponseAuthentication no  # Kerberos options #KerberosAuthentication no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes #KerberosGetAFSToken no #KerberosUseKuserok yes  # GSSAPI options GSSAPIAuthentication yes GSSAPICleanupCredentials no #GSSAPIStrictAcceptorCheck yes #GSSAPIKeyExchange no #GSSAPIEnablek5users no  # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will # be allowed through the ChallengeResponseAuthentication and # PasswordAuthentication. Depending on your PAM configuration, # PAM authentication via ChallengeResponseAuthentication may bypass # the setting of "PermitRootLogin without-password". # If you just want the PAM account and session checks to run without # PAM authentication, then enable this but set PasswordAuthentication # and ChallengeResponseAuthentication to 'no'. # WARNING: 'UsePAM no' is not supported in Red Hat Enterprise Linux and may cause several # problems. UsePAM yes  #AllowAgentForwarding yes #AllowTcpForwarding yes #GatewayPorts no X11Forwarding yes #X11DisplayOffset 10 #X11UseLocalhost yes #PermitTTY yes #PrintMotd yes #PrintLastLog yes #TCPKeepAlive yes #UseLogin no #UsePrivilegeSeparation sandbox # Default for new installations. #PermitUserEnvironment no #Compression delayed #ClientAliveInterval 0 #ClientAliveCountMax 3 #ShowPatchLevel no #UseDNS yes #PidFile /var/run/sshd.pid #MaxStartups 10:30:100 #PermitTunnel no #ChrootDirectory none #VersionAddendum none  # no default banner path #Banner none  # Accept locale-related environment variables AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE AcceptEnv XMODIFIERS  # override default of no subsystems Subsystem sftp /usr/libexec/openssh/sftp-server  # Example of overriding settings on a per-user basis #Match User anoncvs # X11Forwarding no # AllowTcpForwarding no # PermitTTY no # ForceCommand cvs server 

/etc/pam.d/sshd:

#%PAM-1.0 auth required pam_sepermit.so auth substack password-auth auth include postlogin # Used with polkit to reauthorize users in remote sessions -auth optional pam_reauthorize.so prepare account required pam_nologin.so account include password-auth password include password-auth # pam_selinux.so close should be the first session rule session required pam_selinux.so close session optional pam_loginuid.so # pam_selinux.so open should only be followed by sessions to be executed in the user context session required pam_selinux.so open env_params session required pam_namespace.so session optional pam_keyinit.so force revoke session include password-auth session include postlogin # Used with polkit to reauthorize users in remote sessions -session optional pam_reauthorize.so prepare 

Das serverseitige Protokoll: Pastebin . Es endet mit:

Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: Accepted publickey for root from 172.16.28.1 port 45040 ssh2: RSA dc:7b:dc:02:bd:87:0b:7a:ad:a0:71:78:e4:18:86:5 Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug1: monitor_child_preauth: root has been authenticated by privileged process Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_get_keystate: Waiting for new keys Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_receive_expect entering: type 26 Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_receive entering Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_newkeys_from_blob: 0x7eff5524bd40(138) Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug2: mac_setup: setup hmac-md5-etm@openssh.com Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_get_keystate: Waiting for second key Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_newkeys_from_blob: 0x7eff5524bd40(138) Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug2: mac_setup: setup hmac-md5-etm@openssh.com Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_get_keystate: Getting compression state Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_get_keystate: Getting Network I/O buffers Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_receive_expect entering: type 122 Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_receive entering Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_send entering: type 123 Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug2: userauth_pubkey: authenticated 1 pkalg ssh-rsa [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_do_pam_account entering [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_send entering: type 102 [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_receive_expect entering: type 103 [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_receive entering [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_do_pam_account returning 1 [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_send_keystate: Sending new keys: 0x7eff55233ce0 0x7eff552382d0 [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_newkeys_to_blob: converting 0x7eff55233ce0 [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_newkeys_to_blob: converting 0x7eff552382d0 [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_send_keystate: New keys have been sent [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_send_keystate: Sending compression state [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_send entering: type 26 [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_send_keystate: Finished sending state [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_send entering: type 122 [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_receive_expect entering: type 123 [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_request_receive entering [preauth] Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug1: monitor_read_log: child log fd closed Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_share_sync: Share sync Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: mm_share_sync: Share sync end Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: ssh_sandbox_parent_finish: finished Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug1: temporarily_use_uid: 0/0 (e=0/0) Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug1: ssh_gssapi_storecreds: Not a GSSAPI mechanism Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug1: restore_uid: 0/0 Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug1: SELinux support disabled Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug1: PAM: establishing credentials Aug 14 09:55:06 rkt-1f29b259-f7a3-45a3-912a-58f401f8da79 sshd[10]: debug3: PAM: opening session 

Das clientseitige Protokoll: Pastebin

Wenn ich PAM deaktiviere (was auf RHEL & CentOS nicht unterstützt wird, sondern nur zum Testen), wird die Sitzung eingerichtet und sofort vom Client beendet (ich gebe die Pastebin in einem Kommentar). Ich habe auch versucht, ...

• Kommentieren Sie die UsePrivilegeSeparation-Sandbox aus
• SELinux im Container deaktiviert (stellt sich heraus, dass es offensichtlich nicht einmal im Inneren installiert ist)

ohne erkennbare Wirkung. Weiß jemand, was PAM dazu bringen könnte, sich so schlecht zu verhalten, dass es nicht einmal eine Fehlermeldung gibt? Ich habe in vielen anderen Threads gesehen, dass PAM in Kombination mit chroot Probleme macht, aber es gibt immer noch explizite Fehlermeldungen, hier scheint es ein plötzlicher Tod zu sein ... (die sshd läuft immer noch)

PS: Könnte jemand mit genügendem Ruf bitte ein rkt-Tag erstellen? Vielen Dank