Hi Richard, On Mon, Nov 27, 2017 at 07:31:21PM +0000, Richard Haines wrote: ... > --- a/net/sctp/socket.c > +++ b/net/sctp/socket.c > @@ -3123,8 +3123,10 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned > > if (asoc) { > if (val == 0) { > + struct sctp_af *af = sp->pf->af; > val = asoc->pathmtu; > - val -= sp->pf->af->net_header_len; > + val -= af->ip_options_len(asoc->base.sk); > + val -= af->net_header_len; > val -= sizeof(struct sctphdr) + > sizeof(struct sctp_data_chunk); > } Right below here there is a call to sctp_frag_point(). That function also needs this tweak. Yes, we should simplify all these calculations. I have a patch to use sctp_frag_point on where it is currently recalculating it on sctp_datamsg_from_user(), but probably should include other places as well. Marcelo -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html