CVE-2023-6516

To keep its cache database efficient, named running as a recursive
resolver occasionally attempts to clean up the database. It uses several
methods, including some that are asynchronous: a small chunk of memory
pointing to the cache element that can be cleaned up is first allocated and
then queued for later processing. It was discovered that if the resolver is
continuously processing query patterns triggering this type of
cache-database maintenance, named may not be able to handle the cleanup
events in a timely manner. This in turn enables the list of queued cleanup
events to grow infinitely large over time, allowing the configured
max-cache-size limit to be significantly exceeded. This issue affects
BIND 9 versions 9.16.0 through 9.16.45 and 9.16.8-S1 through 9.16.45-S1.

Notes