[Samba] FYI: Latest Ubuntu 22.04 hwe kernel update 6.2.0-31 version breaks mount.cifs to vers=1.0 server cifs_mount failed w/return code = -5

[Michael Lueck]

Greetings,

Heads up to the Samba group that I opened the following bug against the Ubuntu 22.04 hwe kernel update 6.2.0-31.

I am thinking it is not due to a SAMBA update as 1) I did not apply a SAMBA package update from Ubuntu 22.04 and 2) toggling the version of the kernel I boot to causes / corrects the SAMBA mount 
issue. Hopefully soon the Ubuntu team will respond.

"Ubuntu 22.04 update to 6.2.0-31 kernel version breaks mount.cifs to vers=1.0 server cifs_mount failed w/return code = -5"
https://bugs.launchpad.net/bugs/2034033

The following versions are the existing/working version:

linux-image-6.2.0-26-generic                  6.2.0-26.26~22.04.1

And the updated/not working version:

linux-image-6.2.0-31-generic                  6.2.0-31.31~22.04.1

And yes I run my system with:

linux-image-generic-hwe-22.04                 6.2.0.31.31~22.04.8


Booted to the 6.2.0-31 kernel version, attempting to do a mount.cifs operation to our Samba NT4 PDC, results in the following output into syslog:

Sep  4 08:03:24 jaakob kernel: [  107.703886] FS-Cache: Loaded
Sep  4 08:03:24 jaakob kernel: [  107.824160] Key type cifs.spnego registered
Sep  4 08:03:24 jaakob kernel: [  107.824169] Key type cifs.idmap registered
Sep  4 08:03:24 jaakob kernel: [  107.824454] Use of the less secure dialect vers=1.0 is not recommended unless required for access to very old servers
Sep  4 08:03:24 jaakob kernel: [  107.824454]
Sep  4 08:03:24 jaakob kernel: [  107.824457] CIFS: VFS: Use of the less secure dialect vers=1.0 is not recommended unless required for access to very old servers
Sep  4 08:03:24 jaakob kernel: [  107.824460] CIFS: Attempting to mount \\ldslnx01\data
Sep  4 08:03:24 jaakob kernel: [  107.859554] CIFS: VFS: cifs_mount failed w/return code = -5

And none of the Samba mounts will establish.

Booting back to the prior 6.2.0-26 kernel version, Samba mounts work just fine.

I use the following switches to the mount.cifs command in order to establish connections to our Samba NT4 PDC:

"-o
credentials=/home/mdlueck/.smbcredentials,uid=mdlueck,gid=mdlueck,dir_mode=0777,file_mode=0666,nobrl,vers=1.0"


That last vers= option was the last that needed to be added to continue making use of our Samba NT4 style PDC.

Since it is a version upgrade of only the kernel, not Samba package, I would not think that yet another switch to mount.cifs was needed in order to continue connecting successfully. So did the latest 
Kernel  update suddenly break Samba's mount.cifs vers=1.0 support?

Nothing gets logged to our Samba server for the failed mount attempt.


Dropped back to the just prior kernel version as a successful workaround.

I am thankful,

-- 
Michael Lueck
Lueck Data Systems
http://www.lueckdatasystems.com/