From: Xin Long <lucien....@gmail.com>
Date: Thu, 15 Dec 2016 23:00:55 +0800
> Since commit 7fda702f9315 ("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: 7fda702f9315 ("sctp: use new rhlist interface on sctp transport
> rhashtable")
> Reported-by: Dmitry Vyukov <dvyu...@google.com>
> Signed-off-by: Xin Long <lucien....@gmail.com>
Applied.
