ZFS Security issues with snapshots for (longer term) backups

[jamie]

It's already possible for root to mount a snapshot at any arbitrary directory. All that is needed is an option to set snapshots not to automount under .zfs/

In fact, all we need would be for the following to work:

# zfs snapshot -o canmount=noauto ZFS:0/usr@test
cannot create snapshots : this property can not be modified for snapshots

 

[Kai Burghardt]

It's already possible for root to mount a snapshot at any arbitrary directory.

Snapshots cannot be directly zfs-mount(8)ed; they are by definition incomplete. Could you demonstrate what you mean?​

All that is needed is an option to set snapshots not to automount under .zfs/

In fact, all we need would be for the following to work:

Well, the new solution is the snapdir=disabled zfsprops(7) value, PR 16587 from 5 days ago closing OpenZFS issue 3963.​

 

[Andriy]

Snapshots cannot be directly zfs-mount(8)ed; they are by definition incomplete. Could you demonstrate what you mean?

zfs snapshots can be mount(8)-ed, though

 

[jamie]

Snapshots cannot be directly zfs-mount(8)ed; they are by definition incomplete. Could you demonstrate what you mean?​

You can unmount it with umount and also mount it with mount -t zfs ...

Well, the new solution is the snapdir=disabled zfsprops(7) value, PR 16587 from 5 days ago closing OpenZFS issue 3963.​

That's perfect!

Thanks JanBeh for pushing this through. Seems that Brian Behlendorf agreed with you!