[SCTP]: Do not increase rwnd when reading partial notification.

When a user reads a partial notification message, do not
update rwnd since notifications must not be counted towards
receive window.

Tested-by: Oliver Roll <mail@oliroll.de>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 401dac618406..894c278c8cdc 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1911,7 +1911,8 @@ SCTP_STATIC int sctp_recvmsg(struct kiocb *iocb, struct sock *sk,
                  * rwnd by that amount. If all the data in the skb is read,
                  * rwnd is updated when the event is freed.
                  */
-                sctp_assoc_rwnd_increase(event->asoc, copied);
+                if (!sctp_ulpevent_is_notification(event))
+                        sctp_assoc_rwnd_increase(event->asoc, copied);
                 goto out;
         } else if ((event->msg_flags & MSG_NOTIFICATION) ||
                    (event->msg_flags & MSG_EOR))