From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH net-next] net: bridge: Lock before br_fdb_find() Date: Mon, 28 May 2018 10:42:53 -0700 Message-ID: <20180528104253.64e10ffc@xeon-e3> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: bridge@lists.linux-foundation.org, netdev@vger.kernel.org, davem@davemloft.net To: Petr Machata Return-path: Received: from mail-pf0-f193.google.com ([209.85.192.193]:34188 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932072AbeE1Rm5 (ORCPT ); Mon, 28 May 2018 13:42:57 -0400 Received: by mail-pf0-f193.google.com with SMTP id a14-v6so6116527pfi.1 for ; Mon, 28 May 2018 10:42:57 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 28 May 2018 17:44:16 +0200 Petr Machata wrote: > Callers of br_fdb_find() need to hold the hash lock, which > br_fdb_find_port() doesn't do. Add the missing lock/unlock > pair. > > Signed-off-by: Petr Machata > --- > net/bridge/br_fdb.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c > index b19e310..3f5691a 100644 > --- a/net/bridge/br_fdb.c > +++ b/net/bridge/br_fdb.c > @@ -135,9 +135,11 @@ struct net_device *br_fdb_find_port(const struct net_device *br_dev, > return NULL; > > br = netdev_priv(br_dev); > + spin_lock_bh(&br->hash_lock); > f = br_fdb_find(br, addr, vid); > if (f && f->dst) > dev = f->dst->dev; > + spin_unlock_bh(&br->hash_lock); > > return dev; > } Sigh. when did br_fdb_find start needing hash_lock? What is the point of RCU then?