Re: [9fans] security questions

["Devon H. O'Dell" <devon.odell@gmail.com>]

2009/4/16 erik quanstrom <quanstro@quanstro.net>:
>> Right, we're saying the same thing backwards. I just am not sure why
>> smalloc was brought up. Yes, it is able to sleep until memory is
>> available for the operation, but it's not used *everywhere*.
>
> that's part of my point.  sometimes smalloc is appropriate,
> sometimes it is not.  it depends on other things than just
> what you are going to use the allocation for.
>
> do you have a particular, concrete example?

No, you brought it up first, asking if I had looked at it. I think
this particular thread of discussion is agreed upon and tangential.

>> > but what they aren't doing is writing fork bomb programs or programs
>> > that fuzz device drivers.
>>
>> Right, and that's a real threat.
>
> but you can't defend against it unless you decide you
> can have exactly n processes per system and each one can
> have 1/n * userlandsize bytes of memory.  you could divvy
> up memory by user to be a little bit more flexable, but
> providing hard guarantees is going to be very limiting.

Yeah, that's part of the reason I posted here, was to see if other
people had different ideas. This usually isn't a bad place to pull in
thoughts and solutions. And of course processes aren't the only
`potential evil.'

I agree that my solution may not be the best one. But I can't come up
with anything better right now, and at least this seems
semi-Plan-9-ish.

> don't forget about the stack overcommitment issue.

Heh.

>> Yes, there are, but it doesn't mean that it's an invalid assumption.
>> If you're arguing that my point is invalid because it's not a proper
>> application of Plan 9, I'd argue that Plan 9 isn't fit for the
>> Internet, where there are malicious users and script kiddies.
>
> i just stated what i thought the historical situation was.  the
> point was only that changing direction will be difficult.

This thread certainly proves that :)

> i don't think the second part of your argument holds.
> defending from a local threat (like a fork bomb) is much different
> from defending against script kiddies.  it's also much harder.
>
> also, script kiddies don't do a good job of targeting plan 9.

Point taken.

>> If you don't want to run Plan 9 there, ok. Maybe I'm the only one on
>> the list who does. Maybe someone will come out later who also wants
>> to.
>
> if i didn't think this could be useful, i wouldn't
> bother replying.

Point taken :). So are there other / better ideas? Did anybody else
read that paper about Viengoos?

> - erik

--dho