Patch "sctp: set sender next_tsn for the old result with ctsn_ack_point plus 1" has been added to the 4.14-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

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

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     sctp-set-sender-next_tsn-for-the-old-result-with-ctsn_ack_point-plus-1.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Feb  1 13:45:42 CET 2018
From: Xin Long <lucien.xin@gmail.com>
Date: Sat, 25 Nov 2017 21:05:36 +0800
Subject: sctp: set sender next_tsn for the old result with ctsn_ack_point plus 1

From: Xin Long <lucien.xin@gmail.com>


[ Upstream commit 52a395896a051a3d5c34fba67c324f69ec5e67c6 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/sctp/stream.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -541,7 +541,7 @@ struct sctp_chunk *sctp_process_strreset
 		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;
 		}


Patches currently in stable-queue which might be from lucien.xin@gmail.com are

queue-4.14/sctp-set-sender-next_tsn-for-the-old-result-with-ctsn_ack_point-plus-1.patch
queue-4.14/sctp-only-allow-the-asoc-reset-when-the-asoc-outq-is-empty.patch
queue-4.14/sctp-avoid-flushing-unsent-queue-when-doing-asoc-reset.patch