Crash in transfers
The zone xyzabc.com has an update. In the newly AXFR'd data, two of the nodes have the same data:
*.pager. 7200 IN MX 30 pager.qqq.net.
pager.xyzabc.com. 7200 IN MX 30 pager.qqq.net.
The first is out-of-zone, and so is ignored. Its data is freed, but both entries appear to share rr domain name data, so the data for the valid entry is also freed. When the pager.xyzabc.com. entry is processed, it accesses the freed (and overwritten) data for it, and that is where KNOT crashes.