Patch "sctp: only update outstanding_bytes for transmitted queue when doing prsctp_prune" has been added to the 4.14-stable tree

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

sctp: only update outstanding_bytes for transmitted queue when doing prsctp_prune

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-only-update-outstanding_bytes-for-transmitted-queue-when-doing-prsctp_prune.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 <[email protected]> know about it.

From: Xin Long <[email protected]>
Date: Sat, 25 Nov 2017 21:18:34 +0800
Subject: sctp: only update outstanding_bytes for transmitted queue when doing prsctp_prune

From: Xin Long <[email protected]>

[ Upstream commit d30fc5126efb0c33b7adf5966d3051db2c3d7721 ]

Now outstanding_bytes is only increased when appending chunks into one packet and sending it at 1st time, while decreased when it is about to move into retransmit queue. It means outstanding_bytes value is already decreased for all chunks in retransmit queue.

However sctp_prsctp_prune_sent is a common function to check the chunks in both transmitted and retransmit queue, it decrease outstanding_bytes when moving a chunk into abandoned queue from either of them.

It could cause outstanding_bytes underflow, as it also decreases it's value for the chunks in retransmit queue.

This patch fixes it by only updating outstanding_bytes for transmitted queue when pruning queues for prsctp prio policy, the same fix is also needed in sctp_check_transmitted.

---
 net/sctp/outqueue.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

@@ -368,7 +368,8 @@ static int sctp_prsctp_prune_sent(struct
 		asoc->abandoned_sent[SCTP_PR_INDEX(PRIO)]++;
 		streamout->abandoned_sent[SCTP_PR_INDEX(PRIO)]++;
 
-		if (!chk->tsn_gap_acked) {
+		if (queue != &asoc->outqueue.retransmit &&
+		    !chk->tsn_gap_acked) {
 			if (chk->transport)
 				chk->transport->flight_size -=
 						sctp_data_size(chk);

@@ -1429,7 +1430,8 @@ static void sctp_check_transmitted(struc
 			/* If this chunk has not been acked, stop
 			 * considering it as 'outstanding'.
 			 */
-			if (!tchunk->tsn_gap_acked) {
+			if (transmitted_queue != &q->retransmit &&
+			    !tchunk->tsn_gap_acked) {
 				if (tchunk->transport)
 					tchunk->transport->flight_size -=
 							sctp_data_size(tchunk);

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/sctp-only-update-outstanding_bytes-for-transmitted-queue-when-doing-prsctp_prune.patch queue-4.14/sctp-set-frag_point-in-sctp_setsockopt_maxseg-correctly.patch