sctp: set new_asoc temp when processing dupcookie

After sctp changed to use transport hashtable, a transport would be
added into global hashtable when adding the peer to an asoc, then
the asoc can be got by searching the transport in the hashtbale.

The problem is when processing dupcookie in sctp_sf_do_5_2_4_dupcook,
a new asoc would be created. A peer with the same addr and port as
the one in the old asoc might be added into the new asoc, but fail
to be added into the hashtable, as they also belong to the same sk.

It causes that sctp's dupcookie processing can not really work.

Since the new asoc will be freed after copying it's information to
the old asoc, it's more like a temp asoc. So this patch is to fix
it by setting it as a temp asoc to avoid adding it's any transport
into the hashtable and also avoid allocing assoc_id.

An extra thing it has to do is to also alloc stream info for any
temp asoc, as sctp dupcookie process needs it to update old asoc.
But I don't think it would hurt something, as a temp asoc would
always be freed after finishing processing cookie echo packet.

Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 4f5e6cfc7f60..f863b5573e42 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -2088,6 +2088,9 @@ sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net,
 		}
 	}
 
+	/* Set temp so that it won't be added into hashtable */
+	new_asoc->temp = 1;
+
 	/* Compare the tie_tag in cookie with the verification tag of
 	 * current association.
 	 */