From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: [patch net 2/3] team: move add to port list before port enablement Date: Sat, 8 Jun 2013 15:00:54 +0200 Message-ID: <1370696455-12221-3-git-send-email-jiri@resnulli.us> References: <1370696455-12221-1-git-send-email-jiri@resnulli.us> Cc: davem@davemloft.net, eric.dumazet@gmail.com, fbl@redhat.com To: netdev@vger.kernel.org Return-path: Received: from mail-ee0-f41.google.com ([74.125.83.41]:54444 "EHLO mail-ee0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751530Ab3FHNBF (ORCPT ); Sat, 8 Jun 2013 09:01:05 -0400 Received: by mail-ee0-f41.google.com with SMTP id d17so735293eek.28 for ; Sat, 08 Jun 2013 06:01:04 -0700 (PDT) In-Reply-To: <1370696455-12221-1-git-send-email-jiri@resnulli.us> Sender: netdev-owner@vger.kernel.org List-ID: team_port_enable() adds port to port_hashlist. Reader sees port in team_get_port_by_index_rcu() and returns it, but team_get_first_port_txable_rcu() tries to go through port_list, where the port is not inserted yet -> NULL pointer dereference. Fix this by reordering port_list and port_hashlist insertion. Panic is easily triggeable when txing packets and adding/removing port in a loop. Introduced by commit 3d249d4c "net: introduce ethernet teaming device" Signed-off-by: Jiri Pirko --- drivers/net/team/team.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c index d016a76..b305105 100644 --- a/drivers/net/team/team.c +++ b/drivers/net/team/team.c @@ -1092,8 +1092,8 @@ static int team_port_add(struct team *team, struct net_device *port_dev) } port->index = -1; - team_port_enable(team, port); list_add_tail_rcu(&port->list, &team->port_list); + team_port_enable(team, port); __team_compute_features(team); __team_port_change_port_added(port, !!netif_carrier_ok(port_dev)); __team_options_change_check(team); -- 1.7.11.7