Have you experimented with a newer kernel (e.g. Ubuntu 19 or the download from the Ubuntu mainline kernel download site) to see if some of Paulo's DFS fixes (e.g. a large set went in last year) help. On Wed, Nov 27, 2019 at 6:20 AM <abrosich@xxxxxxxx> wrote: > > > Hello, > > I'm trying to configure a linux client (Unubtu 18.04.3) to mount a DFS > share from a windows server 2019. Both machines are joined in the same > Active Directory domain. I joined the linux client using the "realm" > command and it works fine: for example I can login with ssh using AD > credentials. > > The package cifs-utils is version 6.8. > > I start by saying that I have a little konwledge of the windows world > and in particular of SMB, hence my question could by silly but I > searched for days without find any solution. > > I found the following entries in the krb5.conf file (I suppose added by > "realm" coomand): > 3 11/11/19 08:54:09 host/LINUXCLIENT@AD.DOMAIN (des-cbc-crc) > 3 11/11/19 08:54:09 host/LINUXCLIENT@AD.DOMAIN (des-cbc-md5) > 3 11/11/19 08:54:09 host/LINUXCLIENT@AD.DOMAIN (arcfour-hmac) > 3 11/11/19 08:54:09 host/LINUXCLIENT@AD.DOMAIN (aes128-cts-hmac- > sha1-96) > 3 11/11/19 08:54:09 host/LINUXCLIENT@AD.DOMAIN (aes256-cts-hmac- > sha1-96) > 3 11/11/19 08:54:09 host/linuxclient@AD.DOMAIN (des-cbc-crc) > 3 11/11/19 08:54:09 host/linuxclient@AD.DOMAIN (des-cbc-md5) > 3 11/11/19 08:54:09 host/linuxclient@AD.DOMAIN (arcfour-hmac) > 3 11/11/19 08:54:09 host/linuxclient@AD.DOMAIN (aes128-cts-hmac- > sha1-96) > 3 11/11/19 08:54:09 host/linuxclient@AD.DOMAIN (aes256-cts-hmac- > sha1-96) > > I created on the Domain Controller a user principal "linuxclientuser- > cifs" and associated to it an SPN "cifs/linuxclient.fqdn@AD.DOMAIN". I > exported the keytab file and added it in krb5.keytab where I have now > the followind entries: > > 3 11/12/19 12:50:59 cifs/linuxclient.fqdn@AD.DOMAIN (des-cbc-crc) > 3 11/12/19 12:50:59 cifs/linuxclient.fqdn@AD.DOMAIN (des-cbc-md5) > 3 11/12/19 12:50:59 cifs/linuxclient.fqdn@AD.DOMAIN (arcfour-hmac) > 3 11/12/19 12:50:59 cifs/linuxclient.fqdn@AD.DOMAIN (aes256-cts- > hmac-sha1-96) > 3 11/12/19 12:50:59 cifs/linuxclient.fqdn@AD.DOMAIN (aes128-cts- > hmac-sha1-96) > > > I use the following command to mount the share: > sudo mount --verbose --types cifs //winsrv/CifsShare /mnt/cifs -- > options > sec=krb5,multiuser,vers=3,user=cifs/linuxclient.fqdn,domain=AD.DOMAIN > > and the response is: "mount error(13): Permission denied" > > Looking at logs I find: > Nov 27 13:07:18 linuxclient cifs.upcall: key description: > cifs.spnego;0;0;39010000;ver=0x2;host=winsrv;ip4=XXX.XXX.XXX.XXX;sec=kr > b5;uid=0x0;creduid=0x0;user=cifs/linuxclient.fqdn;pid=0x6ac > Nov 27 13:07:18 linuxclient cifs.upcall: ver=2 > Nov 27 13:07:18 linuxclient cifs.upcall: host=winsrv > Nov 27 13:07:18 linuxclient cifs.upcall: ip=XXX.XXX.XXX.XXX > Nov 27 13:07:18 linuxclient cifs.upcall: sec=1 > Nov 27 13:07:18 linuxclient cifs.upcall: uid=0 > Nov 27 13:07:18 linuxclient cifs.upcall: creduid=0 > Nov 27 13:07:18 linuxclient cifs.upcall: user=cifs/linuxclient.fqdn > Nov 27 13:07:18 linuxclient cifs.upcall: pid=1708 > Nov 27 13:07:18 linuxclient cifs.upcall: > get_cachename_from_process_env: pid == 0 > Nov 27 13:07:18 linuxclient cifs.upcall: get_existing_cc: default > ccache is FILE:/tmp/krb5cc_0 > Nov 27 13:07:18 linuxclient cifs.upcall: get_tgt_time: unable to get > principal > Nov 27 13:07:18 linuxclient cifs.upcall: handle_krb5_mech: getting > service ticket for winsrv > Nov 27 13:07:18 linuxclient cifs.upcall: handle_krb5_mech: obtained > service ticket > Nov 27 13:07:18 linuxclient cifs.upcall: Exit status 0 > > > where it says that it get the service ticket (I can see it sniffing > packets with wireshark) but it is "unable to get principal". Which > principal? > > On the server side I have the following error: > > A process has requested access to an object, but has not been granted > those access rights. (0xC0000022) > SPN: session setup failed before the SPN could be queried > SPN Validation Policy: SPN optional / no validation > > > What I'm doing wrong? > > Any suggest is welcome. > > Best regards > > Alberto > > -- Thanks, Steve
