[Pljava-dev] threads left running after function end

[Kris Jurka]

On Fri, 10 Oct 2008, Thomas Hallgren wrote:

> Keep in mind that the JVM has at least one thread that does garbage 
> collection. It might have other threads as well that performs other type 
> of maintenance. Such thread will never access the database and it's 
> probably a bad thing to keep them from doing their work.

That's OK because the calls to Thread only look at the current (and sub) 
ThreadGroups.  The JVM threads are elsewhere and are not found.

Unfortunately just ensuring that all threads end before function return is 
not enough to plug the security hole.  If a trusted function calls an 
untrusted function, as soon as the untrusted function is invoked, the 
SecurityManager is replaced and another thread of the trusted function can 
do nefarious things.  Instead of two SecurityManagers that get switched 
back and forth, we need a single SecurityManager that can tell in what 
context it's being used.  Unfortunately I have no idea how to do that at 
the moment.

Without a fix to this I don't see any alternative to dropping the trusted 
version of pljava.

Kris Jurka