[openib-general] Re: CM patch for 2.6.17 merge

[Michael S. Tsirkin]

Quoting r. Roland Dreier <rdreier at cisco.com>:
> Subject: Re: CM patch for 2.6.17 merge
> 
>     Roland>  Not sure I understand this.  What's the exploit?
> 
>     Michael> Connecting from userspace to an SDP socket. People expect
>     Michael> sockets to be kernel-level.
> 
> Without SDP upstream I don't see the security issue.

We are protecting the remote system here.
Think about time when SDP/CMA are upstream, or about a non-linux
system with SDP/CMA listening, connected over IB to a 2.6.17 linux.

> Even with SDP
> upstream it's dubious: everything coming in from the network should be
> untrusted.

Yes, but e.g. in linux sending e.g. arp packets i slimited for priviledged
users. I agree its weak but ...

> I don't see how you can prevent userspace from sending CM
> messages on an arbitrary UD QP.

Does IB spec require me to accept them?
Maybe we should validate the source QP ...

-- 
Michael S. Tsirkin
Staff Engineer, Mellanox Technologies