From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:41170 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1163652AbeE1Kvs (ORCPT ); Mon, 28 May 2018 06:51:48 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stephen Hemminger , "David S. Miller" , Sasha Levin Subject: [PATCH 4.14 235/496] hv_netvsc: fix locking for rx_mode Date: Mon, 28 May 2018 12:00:20 +0200 Message-Id: <20180528100329.810379683@linuxfoundation.org> In-Reply-To: <20180528100319.498712256@linuxfoundation.org> References: <20180528100319.498712256@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stephen Hemminger [ Upstream commit 35a57b7fef136fa3d5b735ba773f191b95110fa0 ] The rx_mode operation handler is different than other callbacks in that is not always called with rtnl held. Therefore use RCU to ensure that references are valid. Fixes: bee9d41b37ea ("hv_netvsc: propagate rx filters to VF") Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/hyperv/netvsc_drv.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -89,15 +89,20 @@ static void netvsc_change_rx_flags(struc static void netvsc_set_rx_mode(struct net_device *net) { struct net_device_context *ndev_ctx = netdev_priv(net); - struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev); - struct netvsc_device *nvdev = rtnl_dereference(ndev_ctx->nvdev); + struct net_device *vf_netdev; + struct netvsc_device *nvdev; + rcu_read_lock(); + vf_netdev = rcu_dereference(ndev_ctx->vf_netdev); if (vf_netdev) { dev_uc_sync(vf_netdev, net); dev_mc_sync(vf_netdev, net); } - rndis_filter_update(nvdev); + nvdev = rcu_dereference(ndev_ctx->nvdev); + if (nvdev) + rndis_filter_update(nvdev); + rcu_read_unlock(); } static int netvsc_open(struct net_device *net)