Patch "sctp: reinit stream if stream outcnt has been change by sinit in sendmsg" 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: reinit stream if stream outcnt has been change by sinit in sendmsg

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-reinit-stream-if-stream-outcnt-has-been-change-by-sinit-in-sendmsg.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 Sun Jan 28 17:35:08 CET 2018
From: Xin Long <lucien.xin@gmail.com>
Date: Mon, 15 Jan 2018 17:01:19 +0800
Subject: sctp: reinit stream if stream outcnt has been change by sinit in sendmsg

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


[ Upstream commit 625637bf4afa45204bd87e4218645182a919485a ]

After introducing sctp_stream structure, sctp uses stream->outcnt as the
out stream nums instead of c.sinit_num_ostreams.

However when users use sinit in cmsg, it only updates c.sinit_num_ostreams
in sctp_sendmsg. At that moment, stream->outcnt is still using previous
value. If it's value is not updated, the sinit_num_ostreams of sinit could
not really work.

This patch is to fix it by updating stream->outcnt and reiniting stream
if stream outcnt has been change by sinit in sendmsg.

Fixes: a83863174a61 ("sctp: prepare asoc stream for stream reconf")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/sctp/socket.c |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1880,8 +1880,14 @@ static int sctp_sendmsg(struct sock *sk,
 		 */
 		if (sinit) {
 			if (sinit->sinit_num_ostreams) {
-				asoc->c.sinit_num_ostreams =
-					sinit->sinit_num_ostreams;
+				__u16 outcnt = sinit->sinit_num_ostreams;
+
+				asoc->c.sinit_num_ostreams = outcnt;
+				/* outcnt has been changed, so re-init stream */
+				err = sctp_stream_init(&asoc->stream, outcnt, 0,
+						       GFP_KERNEL);
+				if (err)
+					goto out_free;
 			}
 			if (sinit->sinit_max_instreams) {
 				asoc->c.sinit_max_instreams =


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

queue-4.14/sctp-do-not-allow-the-v4-socket-to-bind-a-v4mapped-v6-address.patch
queue-4.14/sctp-reinit-stream-if-stream-outcnt-has-been-change-by-sinit-in-sendmsg.patch
queue-4.14/pppoe-take-needed_headroom-of-lower-device-into-account-on-xmit.patch
queue-4.14/sctp-return-error-if-the-asoc-has-been-peeled-off-in-sctp_wait_for_sndbuf.patch
queue-4.14/netlink-reset-extack-earlier-in-netlink_rcv_skb.patch