--- x/net/sctp/outqueue.c
+++ y/net/sctp/outqueue.c
@@ -88,6 +88,8 @@ static inline void sctp_outq_tail_data(s
 
 	stream = sctp_chunk_stream_no(ch);
 	oute = SCTP_SO(&q->asoc->stream, stream)->ext;
+	if (!oute)
+		return;
 	list_add_tail(&ch->stream_list, &oute->outq);
 }