[cifs-protocol] dNSProperty parsing of DSPROPERTY_ZONE_NS_SERVERS_DA in particular [120040622000005]

[Andrew Bartlett]

G'Day Obiad,

Any news on this one?

Thanks,

Andrew Bartlett

On Mon, 2020-04-06 at 01:44 +0000, Obaid Farooqi via cifs-protocol
wrote:
> Hi Andrew:
> Thanks for contacting Microsoft. I have created a case to track this
> issue. A member of the open specifications team will be in touch
> soon.
> 
> Regards,
> Obaid Farooqi
> Escalation Engineer | Microsoft
> 
> -----Original Message-----
> From: Andrew Bartlett <abartlet at samba.org> 
> Sent: Sunday, April 5, 2020 6:44 PM
> To: Interoperability Documentation Help <dochelp at microsoft.com>;
> cifs-protocol mailing list <cifs-protocol at lists.samba.org>
> Subject: [EXTERNAL] dNSProperty parsing of
> DSPROPERTY_ZONE_NS_SERVERS_DA in particular
> 
> G'Day Dochelp,
> 
> I'm hoping for a little help with interoperability here.  The
> situation is a Samba AD Domain that has also had a Windows AD DC in
> it, so some records were not created by Samba, like this records in
> the DNS partition.
> 
> In the 
> 
> DC=_msdcs.X.Y,CN=MicrosoftDNS,DC=ForestDnsZones,DC=X,DC=Y
> 
> record, there is an attribute:
> 
> dNSProperty:: AAAAAAAAAAAAAAAAAQAAAJIAAAAAAAAA
> 
> 000000 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00
> 00  >................<
> 000010 92 00 00 00 00 00 00 00                          >........<
> 000018
> 
> We, until samba 4.12, would parse this as:
> 
> pull returned Success
>     dnsp_DnsProperty: struct dnsp_DnsProperty
>         wDataLength              : 0x00000000 (0)
>         namelength               : 0x00000000 (0)
>         flag                     : 0x00000000 (0)
>         version                  : 0x00000001 (1)
>         id                       : DSPROPERTY_ZONE_NS_SERVERS_DA
> (146)
>         data                     : union dnsPropertyData(case 0)
>         name                     : 0x00000000 (0)
> dump OK
> 
> However, the wDataLength is 0.  There is not anything in [MS-DNSP]
> 2.3.2.1 dnsProperty to describe any special behaviour for when the id
> suggests that there is a value, but wDataLength is 0.
> 
> 
https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fopenspecs%2Fwindows_protocols%2Fms-dnsp%2F445c7843-e4a1-4222-8c0f-630c230a4c80&data=02%7C01%7Cobaidf%40microsoft.com%7C53955661696c49047dc508d7d9bb33c9%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637217270370382699&sdata=IUnBXWE4A7Ku3aKOxxIt0qNVruGmL2SCrGEirHfaWPg%3D&reserved=0
> 
> We now fail to parse it, because we expect an entry with id
> DSPROPERTY_ZONE_NS_SERVERS_DA to therefore have a valid
> DNS_ADDR_ARRAY (section 2.2.3.2.3). 
> 
> As context (mostly for my fellow team members), we changed it in our
> commit
> 
https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.samba.org%2F%3Fp%3Dsamba.git%3Ba%3Dcommit%3Bh%3Dfee5c6a4247aeac71318186bbff7708d25de5912&data=02%7C01%7Cobaidf%40microsoft.com%7C53955661696c49047dc508d7d9bb33c9%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637217270370382699&sdata=E28dvOwtiXIrLv9cAOAPbA0ZZt8ymFhf41IV2ZKrsfk%3D&reserved=0
> because of bug 
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.samba.org%2Fshow_bug.cgi%3Fid%3D14206&data=02%7C01%7Cobaidf%40microsoft.com%7C53955661696c49047dc508d7d9bb33c9%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637217270370382699&sdata=g2eUwHHxb34BENWmCFMiLdooqEwX0fIpJ0sAVfl3AVk%3D&reserved=0
> which was due to the artificial environment of the fuzzer.
> 
> Can you clarify how this should be interpreted, so we can fix this
> properly?
> 
> Thanks!
> 
> Andrew Bartlett
> 
-- 
Andrew Bartlett                       https://samba.org/~abartlet/
Authentication Developer, Samba Team  https://samba.org
Samba Developer, Catalyst IT          
https://catalyst.net.nz/services/samba