sctp: improve the events for sctp stream adding

[ Upstream commit 8220c870 ]

This patch is to improve sctp stream adding events in 2 places:

  1. In sctp_process_strreset_addstrm_out(), move up SCTP_MAX_STREAM
     and in stream allocation failure checks, as the adding has to
     succeed after reconf_timer stops for the in stream adding
     request retransmission.

  3. In sctp_process_strreset_addstrm_in(), no event should be sent,
     as no in or out stream is added here.

Fixes: 50a41591 ("sctp: implement receiver-side procedures for the Add Outgoing Streams Request Parameter")
Fixes: c5c4ebb3 ("sctp: implement receiver-side procedures for the Add Incoming Streams Request Parameter")
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/sctp/stream.c

@@ -866,6 +866,14 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out(
 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
 		goto out;
 
+	in = ntohs(addstrm->number_of_streams);
+	incnt = stream->incnt + in;
+	if (!in || incnt > SCTP_MAX_STREAM)
+		goto out;
+
+	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
+		goto out;
+
 	if (asoc->strreset_chunk) {
 		if (!sctp_chunk_lookup_strreset_param(
 			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
@@ -889,14 +897,6 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out(
 		}
 	}
 
-	in = ntohs(addstrm->number_of_streams);
-	incnt = stream->incnt + in;
-	if (!in || incnt > SCTP_MAX_STREAM)
-		goto out;
-
-	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
-		goto out;
-
 	stream->incnt = incnt;
 
 	result = SCTP_STRRESET_PERFORMED;
@@ -966,9 +966,6 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in(
 
 	result = SCTP_STRRESET_PERFORMED;
 
-	*evp = sctp_ulpevent_make_stream_change_event(asoc,
-		0, 0, ntohs(addstrm->number_of_streams), GFP_ATOMIC);
-
 out:
 	sctp_update_strreset_result(asoc, result);
 err: