[Samba] Security permissions issues after changing idmap backend from RID to AUTORID

Partha Sarathi parthasarathi.bl at gmail.com
Fri Jan 8 19:30:24 UTC 2016


adding  samba list

On Fri, Jan 8, 2016 at 10:22 AM, Partha Sarathi <parthasarathi.bl at gmail.com>
wrote:

> Hi,
>
>
> We have a customer who facing security issues after changing RID idmap
> backend to AUTORID.
>
>
> The History of the issue looks as below,
>
> 1) When samba configured with RID idmap backend customer requested to
> change few permissions, product support changed them thru setfacl to edit
> the POSIX ACLS directly rather than adding thru smbcacls/samba-tool ntacl.
>
> 2) Later samba configured with AUTORID with base range as the RID idmap
> range.
>
> 3) Now when customer try to access the share they get "access denied " and
> the get_nt_acl_internal() gives the underlying file system SD with
> legacy_uid_sid conversion. those sid does not match the user sids.
>
> Attached the debug level 10 log for more information on this issue.
>
>
> Note:
>
> The idmap range for RID:
>
> idmap config <DOMAIN> : range = 10000000-109999999
>
> The idmap range for AUTORID:
>
> idmap config *: backend = autorid
>
> idmap config *: range = 10000000-2020000000
>
> idmap config *: rangesize = 100000000
>
>
> Since the the old UIDs are unable to get convert with autorid we see
> failure like as below,
>
>  Primary group is 0 and contains 0 supplementary groups
> [2016/01/04 15:08:21.481290,  4, pid=10718, effective(0, 0), real(0, 0),
> class=passdb] ../source3/passdb/pdb_interface.c:1383(pdb_default_uid_to_sid)
>   pdb_default_uid_to_sid: host has no idea of uid 10000512
> [2016/01/04 15:08:21.481310,  4, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)] ../source3/smbd/sec_ctx.c:424(pop_sec_ctx)
>   pop_sec_ctx (110007232, 110000513) - sec_ctx_stack_ndx = 0
> [2016/01/04 15:08:21.481325, 10, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)]
> ../source3/passdb/lookup_sid.c:1045(legacy_uid_to_sid)
>   LEGACY: uid 10000512 -> sid S-1-22-1-10000512
> [2016/01/04 15:08:21.481344,  4, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)] ../source3/smbd/sec_ctx.c:216(push_sec_ctx)
>   push_sec_ctx(110007232, 110000513) : sec_ctx_stack_ndx = 1
> [2016/01/04 15:08:21.481359,  4, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)] ../source3/smbd/uid.c:485(push_conn_ctx)
>   push_conn_ctx(2539132470) : conn_ctx_stack_ndx = 0
> [2016/01/04 15:08:21.481370,  4, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)] ../source3/smbd/sec_ctx.c:316(set_sec_ctx)
>   setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
> [2016/01/04 15:08:21.481380,  5, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)]
> ../libcli/security/security_token.c:53(security_token_debug)
>   Security token: (NULL)
> [2016/01/04 15:08:21.481389,  5, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)]
> ../source3/auth/token_util.c:629(debug_unix_user_token)
>   UNIX token of user 0
>   Primary group is 0 and contains 0 supplementary groups
> [2016/01/04 15:08:21.481436,  4, pid=10718, effective(0, 0), real(0, 0),
> class=passdb] ../source3/passdb/pdb_interface.c:1383(pdb_default_uid_to_sid)
>   pdb_default_uid_to_sid: host has no idea of uid 10004905
> [2016/01/04 15:08:21.481456,  4, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)] ../source3/smbd/sec_ctx.c:424(pop_sec_ctx)
>   pop_sec_ctx (110007232, 110000513) - sec_ctx_stack_ndx = 0
> [2016/01/04 15:08:21.481467, 10, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)]
> ../source3/passdb/lookup_sid.c:1045(legacy_uid_to_sid)
>   LEGACY: uid 10004905 -> sid S-1-22-1-10004905
> [2016/01/04 15:08:21.481486,  4, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)] ../source3/smbd/sec_ctx.c:216(push_sec_ctx)
>   push_sec_ctx(110007232, 110000513) : sec_ctx_stack_ndx = 1
> [2016/01/04 15:08:21.481500,  4, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)] ../source3/smbd/uid.c:485(push_conn_ctx)
>   push_conn_ctx(2539132470) : conn_ctx_stack_ndx = 0
> [2016/01/04 15:08:21.481511,  4, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)] ../source3/smbd/sec_ctx.c:316(set_sec_ctx)
>   setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
> [2016/01/04 15:08:21.481521,  5, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)]
> ../libcli/security/security_token.c:53(security_token_debug)
>   Security token: (NULL)
> [2016/01/04 15:08:21.481530,  5, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)]
> ../source3/auth/token_util.c:629(debug_unix_user_token)
>   UNIX token of user 0
>
>   get_nt_acl_internal: blob hash does not match for file . - returning
> file system SD mapping.
> [2016/01/04 15:08:21.484342, 10, pid=10718, effective(110007232,
> 110000513), real(110007232, 0), class=vfs]
> ../source3/modules/vfs_acl_common.c:554(get_nt_acl_internal)
>   get_nt_acl_internal: acl for blob hash for . is:
> [2016/01/04 15:08:21.484352,  1, pid=10718, effective(110007232,
> 110000513), real(110007232, 0)] ../librpc/ndr/ndr.c:296(ndr_print_debug)
>        pdesc_next: struct security_descriptor
>           revision                 : SECURITY_DESCRIPTOR_REVISION_1 (1)
>           type                     : 0x9004 (36868)
>                  0: SEC_DESC_OWNER_DEFAULTED
>                  0: SEC_DESC_GROUP_DEFAULTED
>                  1: SEC_DESC_DACL_PRESENT
>                  0: SEC_DESC_DACL_DEFAULTED
>                  0: SEC_DESC_SACL_PRESENT
>                  0: SEC_DESC_SACL_DEFAULTED
>                  0: SEC_DESC_DACL_TRUSTED
>                  0: SEC_DESC_SERVER_SECURITY
>                  0: SEC_DESC_DACL_AUTO_INHERIT_REQ
>                  0: SEC_DESC_SACL_AUTO_INHERIT_REQ
>                  0: SEC_DESC_DACL_AUTO_INHERITED
>                  0: SEC_DESC_SACL_AUTO_INHERITED
>                  1: SEC_DESC_DACL_PROTECTED
>                  0: SEC_DESC_SACL_PROTECTED
>                  0: SEC_DESC_RM_CONTROL_VALID
>                  1: SEC_DESC_SELF_RELATIVE
>           owner_sid                : *
>               owner_sid                : S-1-22-1-65534
>           group_sid                : *
>               group_sid                : S-1-22-2-65534
>           sacl                     : NULL
>           dacl                     : *
>               dacl: struct security_acl
>                   revision                 : SECURITY_ACL_REVISION_NT4 (2)
>                   size                     : 0x017c (380)
>                   num_aces                 : 0x00000010 (16)
>                   aces: ARRAY(16)
>                       aces: struct security_ace
>                           type                     :
> SEC_ACE_TYPE_ACCESS_ALLOWED (0)
>                           flags                    : 0x03 (3)
>                                  1: SEC_ACE_FLAG_OBJECT_INHERIT
>                                  1: SEC_ACE_FLAG_CONTAINER_INHERIT
>                                  0: SEC_ACE_FLAG_NO_PROPAGATE_INHERIT
>                                  0: SEC_ACE_FLAG_INHERIT_ONLY
>                                  0: SEC_ACE_FLAG_INHERITED_ACE
>                               0x03: SEC_ACE_FLAG_VALID_INHERIT (3)
>                                  0: SEC_ACE_FLAG_SUCCESSFUL_ACCESS
>
>
> TO workaround this issue we went back to RID based idmap backend and now
> for some users are not able to login itself and they get the below error.
>
> [2016/01/07 11:39:44.475597,  2, pid=5202]
> ../source3/param/loadparm.c:3582(do_section)
>
>   Processing section "[technologyplanning]"
>
> [2016/01/07 11:39:44.475960,  1, pid=5202]
> ../source3/auth/token_util.c:430(add_local_groups)
>
>  * SID S-1-5-21-3082371790-1274690562-2878062458-5771 ->
> getpwuid(10005771) failed*
>
> [2016/01/07 11:39:44.475993,  1, pid=5202]
> ../source3/auth/auth_generic.c:119(auth3_generate_session_info_pac)
>
>   Failed to map kerberos pac to server info (NT_STATUS_UNSUCCESSFUL)
>
>
>
> Please let me know how we can fix these kind of uid and gid mismatch
> issues. Customer is not willing to reply ACLs form his side.
>
> --
> Thanks & Regards
> -Partha
>



-- 
Thanks & Regards
-Partha


More information about the samba mailing list