From patchwork Sat Mar 16 09:02:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhiqiang Liu X-Patchwork-Id: 1057352 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44LxMm14d4z9ryj for ; Sat, 16 Mar 2019 20:04:20 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726763AbfCPJD0 (ORCPT ); Sat, 16 Mar 2019 05:03:26 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:4694 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726020AbfCPJD0 (ORCPT ); Sat, 16 Mar 2019 05:03:26 -0400 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 23B839FB9A0B9FA92A5F; Sat, 16 Mar 2019 17:03:24 +0800 (CST) Received: from [127.0.0.1] (10.184.225.177) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.408.0; Sat, 16 Mar 2019 17:03:16 +0800 Subject: [PATCH net v3] vxlan: Don't call gro_cells_destroy() before device is unregistered From: Zhiqiang Liu To: Eric Dumazet , David Miller , CC: , , , , , , , References: <20190315162824.732b18ac@elisabeth> <005ad387-8d51-561e-a5b9-8e851e03d5e9@gmail.com> <20190315.110249.648596993203657814.davem@davemloft.net> Message-ID: <457d403f-c40d-8201-b10d-b4bf2f0b5be9@huawei.com> Date: Sat, 16 Mar 2019 17:02:54 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: X-Originating-IP: [10.184.225.177] X-CFilter-Loop: Reflected Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Commit ad6c9986bcb62 ("vxlan: Fix GRO cells race condition between receive and link delete") fixed a race condition for the typical case a vxlan device is dismantled from the current netns. But if a netns is dismantled, vxlan_destroy_tunnels() is called to schedule a unregister_netdevice_queue() of all the vxlan tunnels that are related to this netns. In vxlan_destroy_tunnels(), gro_cells_destroy() is called and finished before unregister_netdevice_queue(). This means that the gro_cells_destroy() call is done too soon, for the same reasons explained in above commit. So we need to fully respect the RCU rules, and thus must remove the gro_cells_destroy() call or risk use after-free. Fixes: 58ce31cca1ff ("vxlan: GRO support at tunnel layer") Signed-off-by: Suanming.Mou Suggested-by: Eric Dumazet Reviewed-by: Stefano Brivio Reviewed-by: Zhiqiang Liu --- V1->V3: - update the commit message suggeted by Eric Dumazet - update Fixes: tag drivers/net/vxlan.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 077f1b9f2761..d76dfed8d9bb 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -4335,10 +4335,8 @@ static void vxlan_destroy_tunnels(struct net *net, struct list_head *head) /* If vxlan->dev is in the same netns, it has already been added * to the list by the previous loop. */ - if (!net_eq(dev_net(vxlan->dev), net)) { - gro_cells_destroy(&vxlan->gro_cells); + if (!net_eq(dev_net(vxlan->dev), net)) unregister_netdevice_queue(vxlan->dev, head); - } } for (h = 0; h < PORT_HASH_SIZE; ++h)