PowerFlex 3.x LDAP Authentication Fails In Ubuntu 16.04 And Higher

Scenario
PowerFlex 3.5 and higher, running on Ubuntu 16.04 and higher does not log in using LDAP and restarts the MDM service. 

Symptoms
SCLI command failure:

 root@ubuntu16-mdm1# date; scli --login --username test_user --password test_password --ldap_authentication
Wed Dec 15 03:09:03 EST 2021
Error: MDM failed command. Status: Communication error

MDM traces show that an LDAP authentication attempt does not even start and MDM service gracefully restarts, mdmNet_AbnormalExitCK: 00334: Will pause the network, with Signal 6 (SIGABRT = commonly used to abort the program if there is critical errors):

 15/12 03:09:03.974587 7efef1ce2db0:mosEventLog_PostInternal:00609: New event added. Message: "Command login received, User: 'test_user'. [9]". Additional info: ". Originating source IP: 127.0.0.1" Severity: Info
15/12 03:09:03.974601 7efef1ce2db0:ldapAuthMgr_GetLdapServiceRefByKey:02332: Failed to get LDAP service object by name - rc: LDAP_SERVICE_NOT_FOUND
15/12 03:09:03.982275 7efef1ce2db0:mdmNet_AbnormalExitCK:00334: Will pause network     <<<<<--- MDM service gracefully prepares for a restart
15/12 03:09:03.982290 7efef1ce2db0:net_Pause:02235: Net paused 1 (reversible 0)
15/12 03:09:03.982310 7efef6a9ddb0:netListen_Mit:00170: Error (ABORTED) accepting on socket 26
15/12 03:09:03.982322 7efef1ce2db0:net_Pause:02235: Net paused 1 (reversible 0)
15/12 03:09:03.982346 7efef1ce2db0:mosOsThrd_DumpBacktraceToTraces:01120: Dumping thread 0x33af7d0 backtrace:
15/12 03:09:03.982347 7efef1ce2db0:mosOsThrd_DumpBacktraceToTraces:01133: Thread 0x33af7d0: frame 0: __fortify_fail+0x5c [0x7eff1426e21c]
15/12 03:09:03.982349 7efef1ce2db0:mosDbg_SignalHandler:00723: ---Termination due to signal 6. PID 16584 Faulting address 0x40c8. errno 0---
15/12 03:09:04.133079 0:mosTrcLayer_Create:00239: ---------- Process started. Version private PowerFlex R3_5.1400.104_Release, CodeBase , Sep 12 2021. PID 20567 ----------
15/12 03:09:04.133096 0:mosTrcLayer_Create:00251: No debug actions enabled
15/12 03:09:04.133162 0:mosXmti_SetLastSdbgOpStatus:00750: Last XMTI status set to XMTI is online.
15/12 03:09:04.133169 0:mosDynamicLib_Open:00093: lib-name: libblkid.so.1
15/12 03:09:04.133304 0:mosDynamicLib_Open:00103: load success lib-name: libblkid.so.1
15/12 03:09:04.133909 0:mosDynamicLib_Open:00093: lib-name: libpmem.so.1.0.0:libpmem.so.1:libpmem.so:/usr/lib64/libpmem.so.1.0.0:/usr/lib64/libpmem.so.1:/usr/lib64/libpmem.so

An example of a successful LDAP authentication and login (on RHEL OS):

 15/12 03:09:28.422220 0x7fd8b1cfddb0:mosEventLog_PostInternal:00609: New event added. Message: "Command login received, User: 'test_user'. [144]". Additional info: ". Originating source IP: 127.0.0.1" Severity: Info
15/12 03:09:28.422354 0x7fd8b1cfddb0:ldapAuthMgr_GetLdapServiceRefByKey:02332: Failed to get LDAP service object by name - rc: LDAP_SERVICE_NOT_FOUND
15/12 03:09:28.422404 0x7fd8b1cfddb0:ldapAuthMgr_Authenticate:00711: base-dn: dc=TESTLDAP,dc=LAB,dc=COM, uri: ldap://TESTLDAP.COM:389, user: test_user, num-groups: 4
15/12 03:09:28.422732 (nil):mosOsThrd_StartFunc:00576: Starting thread () tid 293046
15/12 03:09:28.422888 (nil):mosLdap_SearchUserInDomainGroupsIntr:00463: Initializing - timeout: 8 (1)...
15/12 03:09:28.422911 (nil):mosLdap_InitConInternal:00046: Before ldap_initialize - URI: ldap://TESTLDAP.COM:389
15/12 03:09:28.423112 (nil):mosLdap_InitConInternal:00048: After  ldap_initialize - rc: 0
15/12 03:09:28.423125 (nil):mosLdap_InitConnection:00205: Connection was successfully established to ldap://TESTLDAP.COM:389 ldap service
15/12 03:09:28.423169 (nil):mosLdap_SearchUserInDomainGroupsIntr:00478: username: test_user, search-user: test_user, bind-user: uid=test_user,ou=Operations,dc=TESTLDAP,dc=LAB,dc=COM
15/12 03:09:28.423172 (nil):mosLdap_SearchUserInDomainGroupsIntr:00481: Binding (1)...
15/12 03:09:28.423196 (nil):mosLdap_Bind:00120: Before ldap_sasl_bind - user-name: uid=test_user,ou=Operations,dc=TESTLDAP,dc=LAB,dc=COM, timeout-sec: 8
15/12 03:09:28.423198 (nil):mosLdap_SetTimeout:00072: Set library timeout to: 8 seconds
15/12 03:09:28.433429 (nil):mosLdap_Bind:00130: After ldap_sasl_bind - rc: 0, msg-id: 1
15/12 03:09:28.433458 (nil):mosLdap_Bind:00141: Set timeout to 7 sec
15/12 03:09:28.434458 (nil):mosLdap_Bind:00153: ldap_result: res-type: 0x61, result: 0x7fd86c045260
15/12 03:09:28.434470 (nil):mosLdap_Bind:00182: User id=test_user,ou=Operations,dc=TESTLDAP,dc=LAB,dc=COM was successfully binded to LDAP service
15/12 03:09:28.434475 (nil):mosLdap_SearchUserInDomainGroupsIntr:00532: Time passed till search of group 0: 10 ms
15/12 03:09:28.434478 (nil):mosLdap_SearchUserInDomainGroupsIntr:00538: Searching group: 0, filter: (&(uid=test_user)(memberOf=cn=Lab-Test,ou=Operations,dc=TESTLDAP,dc=LAB,dc=COM))
15/12 03:09:28.434479 (nil):mosLdap_SetTimeout:00072: Set library timeout to: 9 seconds
15/12 03:09:28.436388 (nil):mosLdap_SearchUserInDomainGroupsIntr:00546: Searching group: 0, rc: SUCCESS
15/12 03:09:28.436394 (nil):mosLdap_SearchUserInDomainGroupsIntr:00532: Time passed till search of group 1: 10 ms
15/12 03:09:28.436398 (nil):mosLdap_SearchUserInDomainGroupsIntr:00538: Searching group: 1, filter: (&(uid=test_user)(memberOf=cn=Lab-Test,ou=Operations,dc=TESTLDAP,dc=LAB,dc=COM))
15/12 03:09:28.436401 (nil):mosLdap_SetTimeout:00072: Set library timeout to: 9 seconds
15/12 03:09:28.437628 (nil):mosLdap_SearchUserInDomainGroupsIntr:00546: Searching group: 1, rc: SUCCESS
15/12 03:09:28.437632 (nil):mosLdap_SearchUserInDomainGroupsIntr:00532: Time passed till search of group 2: 20 ms
15/12 03:09:28.437634 (nil):mosLdap_SearchUserInDomainGroupsIntr:00538: Searching group: 2, filter: (&(uid=test_user)(memberOf=cn=Lab-Test,ou=Operations,dc=TESTLDAP,dc=LAB,dc=COM))
15/12 03:09:28.437635 (nil):mosLdap_SetTimeout:00072: Set library timeout to: 9 seconds
15/12 03:09:28.438884 (nil):mosLdap_SearchUserInDomainGroupsIntr:00546: Searching group: 2, rc: SUCCESS
15/12 03:09:28.438890 (nil):mosLdap_SearchUserInDomainGroupsIntr:00532: Time passed till search of group 3: 20 ms
15/12 03:09:28.438894 (nil):mosLdap_SearchUserInDomainGroupsIntr:00538: Searching group: 3, filter: (&(uid=test_user)(memberOf=cn=Lab-Test,ou=Operations,dc=TESTLDAP,dc=LAB,dc=COM))
15/12 03:09:28.438896 (nil):mosLdap_SetTimeout:00072: Set library timeout to: 9 seconds
15/12 03:09:28.440113 (nil):mosLdap_SearchUserInDomainGroupsIntr:00546: Searching group: 3, rc: SUCCESS
15/12 03:09:28.440118 (nil):mosLdap_SearchUserInDomainGroupsIntr:00572: Un-binding...
15/12 03:09:28.441164 (nil):mosLdap_SearchUserInDomainGroupsIntr:00581: User test_user was found in 4 groups - search-user: ccmadm, bind-user: uid=test_user,ou=Operations,dc=TESTLDAP,dc=LAB,dc=COM, rc: SUCCESS, time: 20 ms
15/12 03:09:28.441647 0x7fd8b1cfddb0:ldapAuthMgr_Authenticate:00731: Completed - roles-mask: 0xF
15/12 03:09:28.441730 0x7fd8b1cfddb0:repType_AllocObjects:04767: Allocating 1 objects (first-index: 2) of type SESSION
15/12 03:09:28.441785 0x7fd8b16fadb0:repExtent_IO:03750: Writing to the repository - Extent: 7092, Page: 113778, Size: 8192, Batch size: 1, Last type: SESSION
15/12 03:09:28.445751 0x7fd8b170cdb0:repExtent_IO:03750: Writing to the repository - Extent: 7092, Page: 113778, Size: 8192, Batch size: 1, Last type: SESSION
15/12 03:09:28.447731 0x7fd8b1cfddb0:mosEventLog_PostInternal:00609: New event added. Message: "Command login succeeded. [144]". Additional info: "" Severity: Info

Impact

 LDAP authenticated users cannot log in to the MDM. MDM switchover on each LDAP attempt

It is an OS-related issue, specific to Ubuntu when using OpenLDAP.

When PowerFlex internal function tries to copy the baseDn character number into the authentication request it uses the hard coded LdapDn char[256] character size which is 256, where the maximum for starting a connection request is 128 characters, which is represented by FQDN(char[128]).

The maximum for starting a connection request is 128 characters, as a result, the attempt to send an authentication request causes a buffer overflow.

In other OS, the copy operation copies the minimum of characters in Fqdn (char[128]), which is the real characters number (less than 128). In Ubuntu, it copies the LdapDn char[256] length, which is 256.

Impacted Versions

PowerFlex 3.5.x.x

PowerFlex 3.6.x.x

Fixed In Version

PowerFlex 3.5.1.6

PowerFlex 3.6.0.4