From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8313BC388F7 for ; Mon, 26 Oct 2020 02:59:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E1262222C for ; Mon, 26 Oct 2020 02:59:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dxEFla1r" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1421649AbgJZC7t (ORCPT ); Sun, 25 Oct 2020 22:59:49 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:57174 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389452AbgJZC7t (ORCPT ); Sun, 25 Oct 2020 22:59:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603681187; 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=Wj4XKzYinjtinYOa4SEH9Db7ssmjPWw3m5dgQvIRbIo=; b=dxEFla1r0HXUGjU8Zgvx50F9mjy+oo1k2K53H2Gn0tky06aAVnYLwurqdKN82nBXxaQ/Ae tlRMJbKSv/QSfWN7xfQTAQQIRbqlqAmcDPSqdx0oDQWNL4CFGBXcGOVPkiecxj4mbI0gJO q4uaIYndUZVxUqfnSqT7IoMszH/82PM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-320-SsQjknsqOSaucbGw5t__FQ-1; Sun, 25 Oct 2020 22:59:45 -0400 X-MC-Unique: SsQjknsqOSaucbGw5t__FQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1E8121006C81; Mon, 26 Oct 2020 02:59:44 +0000 (UTC) Received: from [10.72.13.201] (ovpn-13-201.pek2.redhat.com [10.72.13.201]) by smtp.corp.redhat.com (Postfix) with ESMTP id F012E55769; Mon, 26 Oct 2020 02:59:38 +0000 (UTC) Subject: Re: [PATCH net] vhost_vdpa: Return -EFUALT if copy_from_user() fails To: "Michael S. Tsirkin" , Dan Carpenter Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kernel-janitors@vger.kernel.org, kuba@kernel.org References: <20201023120853.GI282278@mwanda> <20201023113326-mutt-send-email-mst@kernel.org> From: Jason Wang Message-ID: <4485cc8d-ac69-c725-8493-eda120e29c41@redhat.com> Date: Mon, 26 Oct 2020 10:59:37 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201023113326-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2020/10/23 下午11:34, Michael S. Tsirkin wrote: > On Fri, Oct 23, 2020 at 03:08:53PM +0300, Dan Carpenter wrote: >> The copy_to/from_user() functions return the number of bytes which we >> weren't able to copy but the ioctl should return -EFAULT if they fail. >> >> Fixes: a127c5bbb6a8 ("vhost-vdpa: fix backend feature ioctls") >> Signed-off-by: Dan Carpenter > Acked-by: Michael S. Tsirkin > Needed for stable I guess. Agree. Acked-by: Jason Wang >> --- >> drivers/vhost/vdpa.c | 10 +++++----- >> 1 file changed, 5 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c >> index 62a9bb0efc55..c94a97b6bd6d 100644 >> --- a/drivers/vhost/vdpa.c >> +++ b/drivers/vhost/vdpa.c >> @@ -428,12 +428,11 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, >> void __user *argp = (void __user *)arg; >> u64 __user *featurep = argp; >> u64 features; >> - long r; >> + long r = 0; >> >> if (cmd == VHOST_SET_BACKEND_FEATURES) { >> - r = copy_from_user(&features, featurep, sizeof(features)); >> - if (r) >> - return r; >> + if (copy_from_user(&features, featurep, sizeof(features))) >> + return -EFAULT; >> if (features & ~VHOST_VDPA_BACKEND_FEATURES) >> return -EOPNOTSUPP; >> vhost_set_backend_features(&v->vdev, features); >> @@ -476,7 +475,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, >> break; >> case VHOST_GET_BACKEND_FEATURES: >> features = VHOST_VDPA_BACKEND_FEATURES; >> - r = copy_to_user(featurep, &features, sizeof(features)); >> + if (copy_to_user(featurep, &features, sizeof(features))) >> + r = -EFAULT; >> break; >> default: >> r = vhost_dev_ioctl(&v->vdev, cmd, argp);