This is a longstanding issue with Bind in various Suse chroot environments.
I first observed it in 10.3, then in SLES11 now in 42.2

The directory /var/lib/named/master is created with root:root ownership. This
causes journal files to not be updated and log errors, like so

Jul  7 07:45:07 ha-server named[19387]: dumping master file:
master/tmp-eDMJedzQvt: open: permission denied
Jul  7 07:48:48 ha-server named[19387]: dumping master file:
master/tmp-dmByKZo1Ay: open: permission denied

This most recently occurred after an automatic update last night. 
Basically every time I do a bind update (myself or an automatic one happens), I
need to manually change permissions to named:named.

Further I am now seeing several root hint errors in the lo each day, like so:

Jul  7 09:00:43 ha-server named[19387]: checkhints: unable to get root NS rrset
from cache: not found

This also appears to be because the file root.hint is in the chroot with
root:root ownership, rather than named.