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sctp: check duplicate node before inserting a new transport

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sctp has changed to use rhlist for transport rhashtable since commit
7fda702f93 ("sctp: use new rhlist interface on sctp transport
rhashtable").

But rhltable_insert_key doesn't check the duplicate node when inserting
a node, unlike rhashtable_lookup_insert_key. It may cause duplicate
assoc/transport in rhashtable. like:

 client (addr A, B)                 server (addr X, Y)
    connect to X           INIT (1)
                        ------------>
    connect to Y           INIT (2)
                        ------------>
                         INIT_ACK (1)
                        <------------
                         INIT_ACK (2)
                        <------------

After sending INIT (2), one transport will be created and hashed into
rhashtable. But when receiving INIT_ACK (1) and processing the address
params, another transport will be created and hashed into rhashtable
with the same addr Y and EP as the last transport. This will confuse
the assoc/transport's lookup.

This patch is to fix it by returning err if any duplicate node exists
before inserting it.

Fixes: 7fda702f93 ("sctp: use new rhlist interface on sctp transport rhashtable")
Reported-by: Fabio M. Di Nitto <fdinitto@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2017-02-17 16:35:24 +08:00 committed by David S. Miller
parent 7e1392fb94
commit cd2b708750
1 changed files with 13 additions and 0 deletions
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13
net/sctp/input.c
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@ -872,6 +872,8 @@ void sctp_transport_hashtable_destroy(void)
int sctp_hash_transport(struct sctp_transport *t)
{
struct sctp_transport *transport;
struct rhlist_head *tmp, *list;
struct sctp_hash_cmp_arg arg;
int err;
@ -882,8 +884,19 @@ int sctp_hash_transport(struct sctp_transport *t)
arg.paddr = &t->ipaddr;
arg.lport = htons(t->asoc->base.bind_addr.port);
list = rhltable_lookup(&sctp_transport_hashtable, &arg,
sctp_hash_params);
rhl_for_each_entry_rcu(transport, tmp, list, node)
if (transport->asoc->ep == t->asoc->ep) {
err = -EEXIST;
goto out;
}
err = rhltable_insert_key(&sctp_transport_hashtable, &arg,
&t->node, sctp_hash_params);
out:
if (err)
pr_err_once("insert transport fail, errno %d\n", err);