KVM exhaustion from routing table "leaks"

[Mike Silbersack]

On Tue, 13 May 2003, Shaun Jurrens wrote:

> Specific questions:
>
> 1. Why do statically added routes assume -cloning?
> 2. Forgive my ignorance, but why is -cloning necessary for the default route?
> 3. Although I haven't done an exhaustive comparison of the content of the
> routing table, why don't cloned routes with Use==0 time out?
> 4. There was a security advisory about a possible DoS dealing with -cloning
> and KVA exhaustion on an earlier -release, was the fix part of the breakage?
> 5. Manual removal of routes with 'Use'==0 does not free up kernel memory, why?

I'm not sure I have time to properly answer your questions, so I'll give a
quick answer.

1.  I'm not aware of any actual memory leaks, and if there are any, we'd
definitely like to fix them.  (Some may have been fixed post 4.7, I'm not
really sure.)

2.  The process by which cloned routes are expired is indeed very poor,
and I'm not surprised that you have many sticking around for long periods
of time.  I had started writing an improved method of cleaning out stale
routes, but stopped when I found out what a mess it was.

3.  Someone said he had his graduate students working on a replacement to
cloned routes, I'm not sure what happened with that. :)

Mike "Silby" Silbersack