Kernel 4.13.0-26 killed my CIFS mount

[pvanryn]

hey all,

Recently upgraded to Kernel 4.13.0-26-generic x86_64 to (partially) mitigate the Spectre / meltdown threat. Upon reboot, I can no longer mount my CIFS drive from the command line. I get

mount error(112): Host is down

even though the host isn't down.

I can still see the drive in my networked drives, and copy files, I just can't attach it to a mount point. If I reboot with the old kernel, everything is fine. I hate to leave my system vulnerable, is there anything else I can try? I have two other mint systems with the old kernel, and they mount the drive w/o any problem.

[vimes666]

This is because the new kernel uses SMB 3.0 as default. This used to be SMB 1.0.
Your server is obviously able to speak SMB 1.0, but no SMB 3.0.
This can be corrected by upgrading your server to SMB 3.0 or
by forcing SMB 1.0 or (2.0 may also work) in your cifs mount statement in fstab, add option vers=1.0.

[JeremyB]

I would strongly suggest using the 4.4 kernels as they will get security patches for another 3 years

[Innz]

This is because the new kernel uses SMB 3.0 as default. This used to be SMB 1.0.
Your server is obviously able to speak SMB 1.0, but no SMB 3.0.
This can be corrected by upgrading your server to SMB 3.0 or
by forcing SMB 1.0 or (2.0 may also work) in your cifs mount statement in fstab, add option vers=1.0.

Awesome you just saved my skin!

[pvanryn]

This is because the new kernel uses SMB 3.0 as default. This used to be SMB 1.0.
Your server is obviously able to speak SMB 1.0, but no SMB 3.0.
This can be corrected by upgrading your server to SMB 3.0 or
by forcing SMB 1.0 or (2.0 may also work) in your cifs mount statement in fstab, add option vers=1.0.

Thank you for the help!