strange SD "transformation"

[Matthieu Patou]

Nadya,

Following our talk I made a deeper inspection on SD for GPO object

nTSecurityDescriptor: 
O:S-1-5-21-4278400893-3540712890-98975817-512G:S-1-5-21-4278400893-3540712890-98975817-512D:PAI(A;CI;RPWPCCDCLCLORCWOWDSDDTSW;;;S-1-5-21-4278400893-3540712890-98975817-519)(A;OI;RPWPCCDCLCLORCWOWDSDDTSW;;;S-1-5-21-4278400893-3540712890-98975817-512)(A;CIIO;RPWPCCDCLCLORCWOWDSDDTSW;;;CO)(A;CIIO;RPWPCCDCLCLORCWOWDSDDTSW;;;CO)(A;CI;RPWPCCDCLCLORCWOWDSDDTSW;;;SY)(A;CI;RPLCLORC;;;AU)(OA;CI;CR;edacfd8f-ffb3-11d1-b41d-00a0c968f939;;AU)(A;CI;RPLCLORC;;;ED)(OA;CIIOID;RP;4c164200-20c0-11d0-a768-00aa006e0529;4828cc14-1437-45bc-9b07-ad6f015e5f28;RU)(OA;CIIOID;RP;4c164200-20c0-11d0-a768-00aa006e0529;bf967aba-0de6-11d0-a285-00aa003049e2;RU)(OA;CIIOID;RP;5f202010-79a5-11d0-9020-00c04fc2d4cf;4828cc14-1437-45bc-9b07-ad6f015e5f28;RU)(OA;CIIOID;RP;5f202010-79a5-11d0-9020-00c04fc2d4cf;bf967aba-0de6-11d0-a285-00aa003049e2;RU)(OA;CIIOID;RP;bc0ac240-79a9-11d0-9020-00c04fc2d4cf;4828cc14-1437-45bc-9b07-ad6f015e5f28;RU)(OA;CIIOID;RP;bc0ac240-79a9-11d0-9020-00c04fc2d4cf;bf967aba-0de6-11d0-a285-00aa0030
49e2;RU)(OA;CIIOID;RP;59ba2f42-79a2-11d0-9020-00c04fc2d3cf;4828cc14-1437-45bc-9b07-ad6f015e5f28;RU)(OA;CIIOID;RP;59ba2f42-79a2-11d0-9020-00c04fc2d3cf;bf967aba-0de6-11d0-a285-00aa003049e2;RU)(OA;CIIOID;RP;037088f8-0ae1-11d2-b422-00a0c968f939;4828cc14-1437-45bc-9b07-ad6f015e5f28;RU)(OA;CIIOID;RP;037088f8-0ae1-11d2-b422-00a0c968f939;bf967aba-0de6-11d0-a285-00aa003049e2;RU)(OA;CIIOID;RP;b7c69e6d-2cc7-11d2-854e-00a0c983f608;bf967a86-0de6-11d0-a285-00aa003049e2;ED)(OA;CIIOID;RP;b7c69e6d-2cc7-11d2-854e-00a0c983f608;bf967a9c-0de6-11d0-a285-00aa003049e2;ED)(OA;CIIOID;RP;b7c69e6d-2cc7-11d2-854e-00a0c983f608;bf967aba-0de6-11d0-a285-00aa003049e2;ED)(OA;CIIOID;RPLCLORC;;4828cc14-1437-45bc-9b07-ad6f015e5f28;RU)(OA;CIIOID;RPLCLORC;;bf967a9c-0de6-11d0-a285-00aa003049e2;RU)(OA;CIIOID;RPLCLORC;;bf967aba-0de6-11d0-a285-00aa003049e2;RU)(OA;CIIOID;RPWPCR;91e647de-d96f-4b70-9557-d63ff4f3ccd8;;PS)(A;CIID;RPWPCRCCDCLCLORCWOWDSDDTSW;;;S-1-5-21-4278400893-3540712890-98975817-519)(A;CIID;LC;;;RU)(A;CII
D;RPWPCRCCLCLORCWOWDSDSW;;;BA)S:AI(OU;CIIDSA;WP;f30e3bbe-9ff0-11d1-b603-0000f80367c1;bf967aa5-0de6-11d0-a285-00aa003049e2;WD)(OU;CIIDSA;WP;f30e3bbf-9ff0-11d1-b603-0000f80367c1;bf967aa5-0de6-11d0-a285-00aa003049e2;WD)

But this kind of object is one of the only one with provided ACL during 
provision. And the provision (see 
source4/setup/provision_group_policy.ldif) set this ACL:

nTSecurityDescriptor: 
O:${DOMAINSID}-512G:${DOMAINSID}-512D:PAI(A;CI;RPWPCCDCLCLORCWOWDSDDTSW;;;${DOMAINSID}-512)(A;CI;RPWPCCDCLCLORCWOWDSDDTSW;;;${DOMAINSID}-519)(A;;RPWPCCDCLCLORCWOWDSDDTSW;;;${DOMAINSID}-512)(A;CIIO;RPWPCCDCLCLORCWOWDSDDTSW;;;CO)(A;CI;RPWPCCDCLCLORCWOWDSDDTSW;;;SY)(A;CI;RPLCLORC;;;AU)(OA;CI;CR;edacfd8f-ffb3-11d1-b41d-00a0c968f939;;AU)(A;CI;RPLCLORC;;;ED)S:AI(OU;CIIDSA;WPWD;;f30e3bc2-9ff0-11d1-b603-0000f80367c1;WD)(OU;CIIOIDSA;WP;f30e3bbe-9ff0-11d1-b603-0000f80367c1;bf967aa5-0de6-11d0-a285-00aa003049e2;WD)(OU;CIIOIDSA;WP;f30e3bbf-9ff0-11d1-b603-0000f80367c1;bf967aa5-0de6-11d0-a285-00aa003049e2;WD)

As you can see it's quite different and I'm wondering where it cames 
from  as if I had a search for the nTSecurityDescriptor just after the 
object is create I get the second SD but once I start samba I get the 
first SD. It seems that it's doing a huge inheritance and I don't know 
why (especially given the fact that the SD has the P flag).

Do you have any explanation ?

Matthieu.