From patchwork Mon Jun 20 05:11:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 12886992 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70F54CCA479 for ; Mon, 20 Jun 2022 05:11:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238219AbiFTFLf (ORCPT ); Mon, 20 Jun 2022 01:11:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238102AbiFTFLd (ORCPT ); Mon, 20 Jun 2022 01:11:33 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E10F1DF17 for ; Sun, 19 Jun 2022 22:11:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1655701892; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vRVhHNu1jFH96XfUUtPDbpNe4wane69cNx7I4Zb9yYc=; b=Kg8KcO8mFSUZBH9Eq/JwWJKMvFrQZmB4SqCvKa0ThYVFhr2AxW+o6hdMpevDUJ1O2uswly qiXAvNd4A0XyqaFRoNUhpHk3cuZs7n4XuPD7qpd33un0EGuSwMLERdYCVycu6i6+TMjN4M AXAvA/cQDOWN2z/A0S7sFwHDw0wbN5U= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-581-xl3k3ciZP72VZ9PXGnP3tQ-1; Mon, 20 Jun 2022 01:11:28 -0400 X-MC-Unique: xl3k3ciZP72VZ9PXGnP3tQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1B0081C05AB5; Mon, 20 Jun 2022 05:11:28 +0000 (UTC) Received: from localhost.localdomain (ovpn-12-16.pek2.redhat.com [10.72.12.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id 49A91C28112; Mon, 20 Jun 2022 05:11:24 +0000 (UTC) From: Jason Wang To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, mst@redhat.com, jasowang@redhat.com Cc: davem@davemloft.net, kuba@kernel.org, erwan.yvin@stericsson.com Subject: [PATCH 2/3] caif_virtio: fix the race between virtio_device_ready() and ndo_open() Date: Mon, 20 Jun 2022 13:11:14 +0800 Message-Id: <20220620051115.3142-3-jasowang@redhat.com> In-Reply-To: <20220620051115.3142-1-jasowang@redhat.com> References: <20220620051115.3142-1-jasowang@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org We used to depend on the virtio_device_ready() that is called after probe() by virtio_dev_probe() after netdev registration. This cause a race between ndo_open() and virtio_device_ready(): if ndo_open() is called before virtio_device_ready(), the driver may start to use the device (e.g TX) before DRIVER_OK which violates the spec. Fixing this by switching to use register_netdevice() and protect the virtio_device_ready() with rtnl_lock() to make sure ndo_open() can only be called after virtio_device_ready(). Fixes: 0d2e1a2926b18 ("caif_virtio: Introduce caif over virtio") Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin --- drivers/net/caif/caif_virtio.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/net/caif/caif_virtio.c b/drivers/net/caif/caif_virtio.c index c677ded81133..66375bea2fcd 100644 --- a/drivers/net/caif/caif_virtio.c +++ b/drivers/net/caif/caif_virtio.c @@ -719,13 +719,21 @@ static int cfv_probe(struct virtio_device *vdev) /* Carrier is off until netdevice is opened */ netif_carrier_off(netdev); + /* serialize netdev register + virtio_device_ready() with ndo_open() */ + rtnl_lock(); + /* register Netdev */ - err = register_netdev(netdev); + err = register_netdevice(netdev); if (err) { + rtnl_unlock(); dev_err(&vdev->dev, "Unable to register netdev (%d)\n", err); goto err; } + virtio_device_ready(vdev); + + rtnl_unlock(); + debugfs_init(cfv); return 0;