From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Ricardo Leitner Date: Thu, 15 Dec 2016 16:43:23 +0000 Subject: Re: [PATCH net] sctp: sctp_epaddr_lookup_transport should be protected by rcu_read_lock Message-Id: <20161215164323.GB4731@localhost.localdomain> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Xin Long Cc: network dev , linux-sctp@vger.kernel.org, davem@davemloft.net, Neil Horman , Dmitry Vyukov On Thu, Dec 15, 2016 at 11:00:55PM +0800, Xin Long wrote: > 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 > Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner > --- > net/sctp/endpointola.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c > index 1f03065..410ddc1 100644 > --- a/net/sctp/endpointola.c > +++ b/net/sctp/endpointola.c > @@ -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; > } > > -- > 2.1.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >