[Semibug] OpenBSD vulnerable to Meltdown & Spectre?

[Jonathan Drews]

On Wed, Jun 07, 2023 at 01:24:06PM -0600, Jonathan Drews wrote:
> On Wed, Jun 07, 2023 at 01:36:03PM -0500, Kyle Willett wrote:
> > Hi Jonathan,
> > 
> > Disabling SMT has helped a lot in mitigating side channel attacks from
> > what I've read on /r/OpenBSD when this question comes up.  Disabling
> > SMT is not a panacea from what I've read though.  Combined with using

What I am asking here is that in order for Spectre and Meltdown to
work they have to deliver a malicious  payload. That payload is inside
a Tcp/Ip packet. If that packet never gets past layer 3 then how can
it affect the computer? Here are the four layers:

4) Transport layer (Tcp, UDP, Icmp)
3) Network layer (Ip) <- PF rules block at this layer
2) Datalink Layer
1) Physical layer 


Now this is for a host based firewall as opposed to a gateway
firewall. If the packet cannot get to layer 4 it can never unpack it's
Spectre or Meltdown payload. Is this a correct assessment?

--
Kind regards,
Jonathan