[Samba] Cifs mount to Netapp filer fails

[Richard Smits]

We have noticed that a CIFS/SMB mount to a CIFS share on our netapp
filer does not work. NTLM mounts work, but if you use KRB5 security it
does not work.

If you try to make a mount the response is : "Input/output error"

There is already a bugreport on this :

https://bugzilla.samba.org/show_bug.cgi?id=6682

Has anyone more information about this so we can work around it ? It has
to do with "extended security negotiation". The mount command we use is
: mount.cifs //server.domain.net/homedir -o sec=krb5i

Note : smbclient with krb5 support works. I have tested this.

A cifs mount to one of our windows server works as expected. (It always has)
After increasing debug info you can see that a working mount to a
windows server shows the following :

fs/cifs/cifssmb.c: Dialect: 2
fs/cifs/asn1.c: OID len = 7 oid = 0x1 0x2 0x348 0xbb92
fs/cifs/asn1.c: OID len = 7 oid = 0x1 0x2 0x348 0x1bb92
fs/cifs/asn1.c: OID len = 8 oid = 0x1 0x2 0x348 0x1bb92
fs/cifs/asn1.c: OID len = 10 oid = 0x1 0x3 0x6 0x1
fs/cifs/cifssmb.c: Must sign - secFlags 0x1009
fs/cifs/cifssmb.c: negprot rc 0

mount that fails (NetApp server):

fs/cifs/cifssmb.c: Dialect: 2
fs/cifs/cifssmb.c: negprot rc -5

Greetings ... Richard Smits