Security Advisory: Server Lockup Upon IXFR or DDNS Update Combined with High Query Rate

[Paul Ebersman]

larissas> When an authoritative server processes a successful IXFR
larissas> transfer or a dynamic update, there is a small window of time
larissas> during which the IXFR/update coupled with a query may cause a
larissas> deadlock to occur.

The issue is a write lock. The bug can be triggered by an inbound zone
transfer or dynamic update. Doesn't matter if it's an incremental or
full zone transfer.