In init_jk of iis/jk_isapi_plugin.c, the worker_env is constructed from a map
allocated in that function, which is subsequently freed before init_jk exits.

The worker names (and some other strings) are copied from the map into the
worker_env, and subsequently into the worker structs themselves.

Later, when the worker name is accessed, freed memory is accessed and bogus data
is used. e.g. p->worker->name in ajp_done in jk_ajp_common.c

Mercifully, the fields concerned seem only to be used in debug logging
statements, so this hasn't caused any crashes - even in debug mode all you see
is a stream of ÝÝÝÝÝÝÝÝ characters.
mod_jk may avoid this issue, as the config map is passed from Apache to the
module, and is presumably kept around, although I haven't tested that theory.