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

sctp: only allow the asoc reset when the asoc outq is empty

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-allow-the-asoc-reset-when-the-asoc-outq-is-empty.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 21:05:34 +0800 Subject: sctp: only allow the asoc reset when the asoc outq is empty

From: Xin Long lucien.xin@gmail.com

[ Upstream commit 5c6144a0eb5366ae07fc5059301b139338f39bbd ]

As it says in rfc6525#section5.1.4, before sending the request,

C2: The sender has either no outstanding TSNs or considers all outstanding TSNs abandoned.

Prior to this patch, it tried to consider all outstanding TSNs abandoned by dropping all chunks in all outqs with sctp_outq_free (even including sacked, retransmit and transmitted queues) when doing this reset, which is too aggressive.

To make it work gently, this patch will only allow the asoc reset when the sender has no outstanding TSNs by checking if unsent, transmitted and retransmit are all empty with sctp_outq_is_empty before sending and processing the request.

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 | 9 +++++++++ 1 file changed, 9 insertions(+)

--- a/net/sctp/stream.c +++ b/net/sctp/stream.c @@ -224,6 +224,9 @@ int sctp_send_reset_assoc(struct sctp_as if (asoc->strreset_outstanding) return -EINPROGRESS;

+ if (!sctp_outq_is_empty(&asoc->outqueue)) + return -EAGAIN; + chunk = sctp_make_strreset_tsnreq(asoc); if (!chunk) return -ENOMEM; @@ -544,6 +547,12 @@ struct sctp_chunk *sctp_process_strreset } goto err; } + + if (!sctp_outq_is_empty(&asoc->outqueue)) { + result = SCTP_STRRESET_IN_PROGRESS; + goto err; + } + asoc->strreset_inseq++;

if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))

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