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%3Ba=su...

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 stable@vger.kernel.org know about it.

From foo@baz Fri Feb 23 11:45:09 CET 2018

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

[ 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.

Fixes: 8dbdf1f5b09c ("sctp: implement prsctp PRIO policy") 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/outqueue.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -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 lucien.xin@gmail.com 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