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sctp: sctp_epaddr_lookup_transport should be protected by rcu_read_lock 

Since commit 7fda702f93 ("sctp: use new rhlist interface on sctp transport
rhashtable"), sctp has changed to use rhlist_lookup to look up transport, but
rhlist_lookup doesn't call rcu_read_lock inside, unlike rhashtable_lookup_fast.

It is called in sctp_epaddr_lookup_transport and sctp_addrs_lookup_transport.
sctp_addrs_lookup_transport is always in the protection of rcu_read_lock(),
as __sctp_lookup_association is called in rx path or sctp_lookup_association
which are in the protection of rcu_read_lock() already.

But sctp_epaddr_lookup_transport is called by sctp_endpoint_lookup_assoc, it
doesn't call rcu_read_lock, which may cause "suspicious rcu_dereference_check
usage' in __rhashtable_lookup.

This patch is to fix it by adding rcu_read_lock in sctp_endpoint_lookup_assoc
before calling sctp_epaddr_lookup_transport.

Fixes: 7fda702f93 ("sctp: use new rhlist interface on sctp transport rhashtable")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
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>
This commit is contained in:
Xin Long 2016-12-15 23:00:55 +08:00 committed by David S. Miller
parent 10a3ecf49b
commit 5cb2cd68dd
1 changed files with 4 additions and 1 deletions
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5
net/sctp/endpointola.c
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@ -331,7 +331,9 @@ struct sctp_association *sctp_endpoint_lookup_assoc(
* on this endpoint.
*/
if (!ep->base.bind_addr.port)
goto out;
return NULL;
rcu_read_lock();
t = sctp_epaddr_lookup_transport(ep, paddr);
if (!t)
goto out;
@ -339,6 +341,7 @@ struct sctp_association *sctp_endpoint_lookup_assoc(
*transport = t;
asoc = t->asoc;
out:
rcu_read_unlock();
return asoc;
}