diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -1963,6 +1963,10 @@ * if seg contains an ACK, but not for our SYN/ACK, send a RST. */ case TCPS_SYN_RECEIVED: + if (thflags & TH_RST) { + /* Handle RST segments later. */ + break; + } if ((thflags & TH_ACK) && (SEQ_LEQ(th->th_ack, tp->snd_una) || SEQ_GT(th->th_ack, tp->snd_max))) { diff --git a/sys/netinet/tcp_syncache.c b/sys/netinet/tcp_syncache.c --- a/sys/netinet/tcp_syncache.c +++ b/sys/netinet/tcp_syncache.c @@ -623,18 +623,6 @@ sc = syncache_lookup(inc, &sch); /* returns locked sch */ SCH_LOCK_ASSERT(sch); - /* - * Any RST to our SYN|ACK must not carry ACK, SYN or FIN flags. - * See RFC 793 page 65, section SEGMENT ARRIVES. - */ - if (tcp_get_flags(th) & (TH_ACK|TH_SYN|TH_FIN)) { - if ((s = tcp_log_addrs(inc, th, NULL, NULL))) - log(LOG_DEBUG, "%s; %s: Spurious RST with ACK, SYN or " - "FIN flag set, segment ignored\n", s, __func__); - TCPSTAT_INC(tcps_badrst); - goto done; - } - /* * No corresponding connection was found in syncache. * If syncookies are enabled and possibly exclusively