Re: [PATCH for-rc] siw: MPA Reply handler tries to read beyond MPA message

[Krishnamraju Eraparaju <krishna2@chelsio.com>]

On Wednesday, July 07/31/19, 2019 at 15:17:40 -0400, Doug Ledford wrote:
> On Wed, 2019-07-31 at 16:03 +0530, Krishnamraju Eraparaju wrote:
> > while processing MPA Reply, SIW driver is trying to read extra 4 bytes
> > than what peer has advertised as private data length.
> > 
> > If a FPDU data is received before even siw_recv_mpa_rr() completed
> > reading MPA reply, then ksock_recv() in siw_recv_mpa_rr() could also
> > read FPDU, if "size" is larger than advertised MPA reply length.
> > 
> >  501 static int siw_recv_mpa_rr(struct siw_cep *cep)
> >  502 {
> >           .............
> >  572
> >  573         if (rcvd > to_rcv)
> >  574                 return -EPROTO;   <----- Failure here
> > 
> > Looks like the intention here is to throw an ERROR if the received
> > data
> > is more than the total private data length advertised by the peer. But
> > reading beyond MPA message causes siw_cm to generate
> > RDMA_CM_EVENT_CONNECT_ERROR event when TCP socket recv buffer is
> > already
> > queued with FPDU messages.
> > 
> > Hence, this function should only read upto private data length.
> > 
> > Signed-off-by: Krishnamraju Eraparaju <krishna2@chelsio.com>
> 
> Once you apply this patch, the if (rcvd > to_rcv) test you listed above
> in the commit message becomes dead code.  So I removed it while applying
> the patch.  Thanks.
> 

Thanks Doug.

> -- 
> Doug Ledford <dledford@redhat.com>
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