From patchwork Mon Aug 15 15:48:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 659329 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3sCg150tNqz9t3R for ; Tue, 16 Aug 2016 01:50:01 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753019AbcHOPtl (ORCPT ); Mon, 15 Aug 2016 11:49:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57690 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753150AbcHOPsx (ORCPT ); Mon, 15 Aug 2016 11:48:53 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8324420279; Mon, 15 Aug 2016 15:48:53 +0000 (UTC) Received: from vitty.brq.redhat.com (vitty.brq.redhat.com [10.34.26.3]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u7FFmiod004749; Mon, 15 Aug 2016 11:48:52 -0400 From: Vitaly Kuznetsov To: netdev@vger.kernel.org Cc: devel@linuxdriverproject.org, linux-kernel@vger.kernel.org, Haiyang Zhang , "K. Y. Srinivasan" , Stephen Hemminger Subject: [PATCH net v2 4/5] hv_netvsc: protect module refcount by checking net_device_ctx->vf_netdev Date: Mon, 15 Aug 2016 17:48:42 +0200 Message-Id: <1471276123-24264-5-git-send-email-vkuznets@redhat.com> In-Reply-To: <1471276123-24264-1-git-send-email-vkuznets@redhat.com> References: <1471276123-24264-1-git-send-email-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Mon, 15 Aug 2016 15:48:53 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We're not guaranteed to see NETDEV_REGISTER/NETDEV_UNREGISTER notifications only once per VF but we increase/decrease module refcount unconditionally. Check vf_netdev to make sure we don't take/release it twice. We presume that only one VF per netvsc device may exist. Signed-off-by: Vitaly Kuznetsov Acked-by: Haiyang Zhang --- drivers/net/hyperv/netvsc_drv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 2c90883..62a4e6e 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -1193,7 +1193,7 @@ static int netvsc_register_vf(struct net_device *vf_netdev) net_device_ctx = netdev_priv(ndev); netvsc_dev = net_device_ctx->nvdev; - if (netvsc_dev == NULL) + if (!netvsc_dev || net_device_ctx->vf_netdev) return NOTIFY_DONE; netdev_info(ndev, "VF registering: %s\n", vf_netdev->name); @@ -1312,7 +1312,7 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev) net_device_ctx = netdev_priv(ndev); netvsc_dev = net_device_ctx->nvdev; - if (netvsc_dev == NULL) + if (!netvsc_dev || !net_device_ctx->vf_netdev) return NOTIFY_DONE; netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name); netvsc_inject_disable(net_device_ctx);