sctp: set sender next_tsn for the old result with ctsn_ack_point plus 1

When doing asoc reset, if the sender of the response has already sent some
chunk and increased asoc->next_tsn before the duplicate request comes, the
response will use the old result with an incorrect sender next_tsn.

Better than asoc->next_tsn, asoc->ctsn_ack_point can't be changed after
the sender of the response has performed the asoc reset and before the
peer has confirmed it, and it's value is still asoc->next_tsn original
value minus 1.

This patch sets sender next_tsn for the old result with ctsn_ack_point
plus 1 when processing the duplicate request, to make sure the sender
next_tsn value peer gets will be always right.

Fixes: 692787cef651 ("sctp: implement receiver-side procedures for the SSN/TSN Reset Request Parameter")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index 9dd5bfe3860c..a20145b3a949 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -725,7 +725,7 @@ struct sctp_chunk *sctp_process_strreset_tsnreq(
                 i = asoc->strreset_inseq - request_seq - 1;
                 result = asoc->strreset_result[i];
                 if (result == SCTP_STRRESET_PERFORMED) {
-                        next_tsn = asoc->next_tsn;
+                        next_tsn = asoc->ctsn_ack_point + 1;
                         init_tsn =
                                 sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1;
                 }