[Samba] corrupted db after upgrading to 4.7

[Maxence Sartiaux]

Hello


last week we updated three domain controllers (Sernet Samba) from 4.2 to 
4.7, typical upgrade path (4.3->4.4->4.5->4.6->4.7), everything was ok.

The next day we got a mail from the Sernet team informing they fixed a 
bug affecting the group memberships.

https://bugzilla.samba.org/show_bug.cgi?id=13095

We've applied the update and few days after the update which should fix 
the bug, we got a database corruption with multiple times the same user 
in a group and the coherency check between all DC was bad.

I tried a dbcheck --cross-ncs --fix --yes, it fixed several errors 
(>2000) but now i still have 372 persistant errors and the dbcheck 
script won't fix them.

The domain is still working great, creating / removing users, edit 
membership, the replication, everything works.

Here's a part of the errors, all of them are "missing backlink" or 
"orphaned backlink".

[root at dc1 ~]# samba-tool dbcheck
Checking 1233 objects
ERROR: orphaned backlink attribute 'memberOf' in CN=Gérard 
Dellaval,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_ila,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Gérard 
Dellaval,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_insertion,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Gérard 
Dellaval,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_report_bud,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Gérard 
Dellaval,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_public_commun,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Gérard 
Dellaval,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_report,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Gérard 
Dellaval,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_applic,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Willy 
Gaspard,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_insertion,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Willy 
Gaspard,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_art_60,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Willy 
Gaspard,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_report_bud,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Willy 
Gaspard,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_public_commun,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Willy 
Gaspard,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_energie,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Willy 
Gaspard,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_accueil,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Willy 
Gaspard,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_ss,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Willy 
Gaspard,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_smd,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
ERROR: missing backlink attribute 'memberOf' in CN=Marine 
Mathias,OU=AC,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cee_03,OU=AC,OU=MGROUPS,DC=contoso,DC=com
......
Not removing orphaned backlink memberOf
ERROR: missing backlink attribute 'memberOf' in CN=Sabine 
Dillien,OU=AC,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cee,OU=AC,OU=MGROUPS,DC=contoso,DC=com
Not fixing missing backlink memberOf
ERROR: missing backlink attribute 'memberOf' in CN=Sabine 
Dillien,OU=AC,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cee,OU=AC,OU=MGROUPS,DC=contoso,DC=com
Not fixing missing backlink memberOf
ERROR: missing backlink attribute 'memberOf' in CN=Sabine 
Dillien,OU=AC,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cee,OU=AC,OU=MGROUPS,DC=contoso,DC=com
Not fixing missing backlink memberOf
ERROR: missing backlink attribute 'memberOf' in CN=Sabine 
Dillien,OU=AC,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cee,OU=AC,OU=MGROUPS,DC=contoso,DC=com
Not fixing missing backlink memberOf
ERROR: missing backlink attribute 'memberOf' in CN=Jean-Paul 
Tistaert,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_applic,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not fixing missing backlink memberOf
ERROR: missing backlink attribute 'memberOf' in CN=Jean-Paul 
Tistaert,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_applic,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not fixing missing backlink memberOf
ERROR: missing backlink attribute 'memberOf' in CN=Cédric De 
Mul,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_applic,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not fixing missing backlink memberOf
ERROR: missing backlink attribute 'memberOf' in CN=Jean-Paul 
Tistaert,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_applic,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not fixing missing backlink memberOf
ERROR: missing backlink attribute 'memberOf' in CN=Cédric De 
Mul,OU=CPAS,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cpas_applic,OU=CPAS,OU=MGROUPS,DC=contoso,DC=com
Not fixing missing backlink memberOf
ERROR: orphaned backlink attribute 'memberOf' in CN=Sabine 
Dillien,OU=AC,OU=MUSERS,DC=contoso,DC=com for link member in 
CN=cee_outils,OU=AC,OU=MGROUPS,DC=contoso,DC=com
Not removing orphaned backlink memberOf
Please use --fix to fix these errors
Checked 1233 objects (372 errors)

Is there any script or update to fix this issue ?


Thanks.