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

sctp: avoid flushing unsent queue when doing asoc reset

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-avoid-flushing-unsent-queue-when-doing-asoc-reset.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 21:05:35 +0800 Subject: sctp: avoid flushing unsent queue when doing asoc reset

From: Xin Long lucien.xin@gmail.com

[ Upstream commit 159f2a7456c6ae95c1e1a58e8b8ec65ef12d51cf ]

Now when doing asoc reset, it cleans up sacked and abandoned queues by calling sctp_outq_free where it also cleans up unsent, retransmit and transmitted queues.

It's safe for the sender of response, as these 3 queues are empty at that time. But when the receiver of response is doing the reset, the users may already enqueue some chunks into unsent during the time waiting the response, and these chunks should not be flushed.

To void the chunks in it would be removed, it moves the queue into a temp list, then gets it back after sctp_outq_free is done.

The patch also fixes some incorrect comments in sctp_process_strreset_tsnreq.

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 | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-)

--- a/net/sctp/stream.c +++ b/net/sctp/stream.c @@ -563,9 +563,10 @@ struct sctp_chunk *sctp_process_strreset goto out; }

- /* G3: The same processing as though a SACK chunk with no gap report - * and a cumulative TSN ACK of the Sender's Next TSN minus 1 were - * received MUST be performed. + /* G4: The same processing as though a FWD-TSN chunk (as defined in + * [RFC3758]) with all streams affected and a new cumulative TSN + * ACK of the Receiver's Next TSN minus 1 were received MUST be + * performed. */ max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map); sctp_ulpq_reasm_flushtsn(&asoc->ulpq, max_tsn_seen); @@ -580,10 +581,9 @@ struct sctp_chunk *sctp_process_strreset sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, init_tsn, GFP_ATOMIC);

- /* G4: The same processing as though a FWD-TSN chunk (as defined in - * [RFC3758]) with all streams affected and a new cumulative TSN - * ACK of the Receiver's Next TSN minus 1 were received MUST be - * performed. + /* G3: The same processing as though a SACK chunk with no gap report + * and a cumulative TSN ACK of the Sender's Next TSN minus 1 were + * received MUST be performed. */ sctp_outq_free(&asoc->outqueue);

@@ -844,6 +844,7 @@ struct sctp_chunk *sctp_process_strreset if (result == SCTP_STRRESET_PERFORMED) { __u32 mtsn = sctp_tsnmap_get_max_tsn_seen( &asoc->peer.tsn_map); + LIST_HEAD(temp);

sctp_ulpq_reasm_flushtsn(&asoc->ulpq, mtsn); sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC); @@ -852,7 +853,13 @@ struct sctp_chunk *sctp_process_strreset SCTP_TSN_MAP_INITIAL, stsn, GFP_ATOMIC);

+ /* Clean up sacked and abandoned queues only. As the + * out_chunk_list may not be empty, splice it to temp, + * then get it back after sctp_outq_free is done. + */ + list_splice_init(&asoc->outqueue.out_chunk_list, &temp); sctp_outq_free(&asoc->outqueue); + list_splice_init(&temp, &asoc->outqueue.out_chunk_list);

asoc->next_tsn = rtsn; asoc->ctsn_ack_point = asoc->next_tsn - 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