From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 24 Feb 2023 03:07:01 -0500 From: "Michael S. Tsirkin" Subject: Re: [virtio-dev] Re: [PATCH v9] virtio-net: support inner header hash Message-ID: <20230224030632-mutt-send-email-mst@kernel.org> References: <20230218143715.841-1-hengqi@linux.alibaba.com> <20230221124518-mutt-send-email-mst@kernel.org> <4d123e32-1ad0-e692-7fa6-0565eb34c487@redhat.com> <0f53212f-a89b-ad3c-73e3-a7a7b5533058@linux.alibaba.com> <1047920c-5dd5-8f31-0c4c-a108f36155f8@redhat.com> <0547edfa-bb75-62bb-9a33-41a9b9603a0e@linux.alibaba.com> MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit To: Jason Wang Cc: Heng Qi , virtio-comment@lists.oasis-open.org, virtio-dev@lists.oasis-open.org, Parav Pandit , Yuri Benditovich , Cornelia Huck , Xuan Zhuo List-ID: On Fri, Feb 24, 2023 at 10:45:13AM +0800, Jason Wang wrote: > > 在 2023/2/23 12:41, Heng Qi 写道: > > > > > > 在 2023/2/23 上午10:50, Jason Wang 写道: > > > Hi: > > > > > > 在 2023/2/22 14:46, Heng Qi 写道: > > > > Hi, Jason. Long time no see. :) > > > > > > > > 在 2023/2/22 上午11:22, Jason Wang 写道: > > > > > > > > > > 在 2023/2/22 01:50, Michael S. Tsirkin 写道: > > > > > > On Sat, Feb 18, 2023 at 10:37:15PM +0800, Heng Qi wrote: > > > > > > > +\subparagraph{Security risks between encapsulated packets and RSS} > > > > > > > +There may be potential security risks when > > > > > > > encapsulated packets using RSS to > > > > > > > +select queues for placement. When a user inside a > > > > > > > tunnel tries to control the > > > > > > > > > > > > > > > What do you mean by "user" here? Is it a remote or local one? > > > > > > > > > > > > > I mean a remote attacker who is not under the control of the > > > > tunnel owner. > > > > > > > > > Anything may the tunnel different? I think this can happen even > > > without tunnel (and even with single queue). > > > > I agree. > > > > > > > > How to mitigate those attackers seems more like a implementation > > > details where might require fair queuing or other QOS technology > > > which has been well studied. > > > > I am also not sure whether this point needs to be focused on in the > > spec, and I see that the protection against tunnel DoS is more protected > > outside the device, > > but it seems to be okay to give some attack reminders. > > > Maybe it's sufficient to say the device should make sure the fairness among > different flows when queuing packets? > > Thanks that isn't really achievable. > > > > > Thanks. > > > > > > > > It seems out of the scope of the spec (unless we want to let driver > > > manageable QOS). > > > > > > Thanks > > > > > > > > > > > > > > Thanks. > > > > > > > > > > > > > > > > +enqueuing of encapsulated packets, then the user > > > > > > > can flood the device with invaild > > > > > > > +packets, and the flooded packets may be hashed into > > > > > > > the same queue as packets in > > > > > > > +other normal tunnels, which causing the queue to overflow. > > > > > > > + > > > > > > > +This can pose several security risks: > > > > > > > +\begin{itemize} > > > > > > > +\item  Encapsulated packets in the normal tunnels > > > > > > > cannot be enqueued due to queue > > > > > > > +       overflow, resulting in a large amount of packet loss. > > > > > > > +\item  The delay and retransmission of packets in > > > > > > > the normal tunnels are extremely increased. > > > > > > > +\item  The user can observe the traffic information > > > > > > > and enqueue information of other normal > > > > > > > +       tunnels, and conduct targeted DoS attacks. > > > > > > > +\end{\itemize} > > > > > > > + > > > > > > Hmm with this all written out it sounds pretty severe. > > > > > > > > > > > > > > > I think we need first understand whether or not it's a > > > > > problem that we need to solve at spec level: > > > > > > > > > > 1) anything make encapsulated packets different or why we > > > > > can't hit this problem without encapsulation > > > > > > > > > > 2) whether or not it's the implementation details that the > > > > > spec doesn't need to care (or how it is solved in real NIC) > > > > > > > > > > Thanks > > > > > > > > > > > > > > > > At this point with no ways to mitigate, I don't feel > > > > > > this is something > > > > > > e.g. Linux can enable.  I am not going to nack the spec patch if > > > > > > others  find this somehow useful e.g. for dpdk. > > > > > > How about CC e.g. dpdk devs or whoever else is going to use this > > > > > > and asking them for the opinion? > > > > > > > > > > > > > > > > > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > > > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org > >