From: Xin Long <lucien.xin@gmail.com>
Date: Tue, 25 Jun 2019 00:21:45 +0800

Now in sctp_endpoint_init(), it holds the sk then creates auth
shkey. But when the creation fails, it doesn't release the sk,
which causes a sk defcnf leak,

Here to fix it by only holding the sk when auth shkey is created
successfully.

Fixes: a29a5bd4f5c3 ("[SCTP]: Implement SCTP-AUTH initializations.")
Reported-by: syzbot+afabda3890cc2f765041@syzkaller.appspotmail.com
Reported-by: syzbot+276ca1c77a19977c0130@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>

Applied and queued up for -stable, thanks Xin.