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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable 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 AC798C43381 for ; Tue, 19 Feb 2019 06:53:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 83B70217D9 for ; Tue, 19 Feb 2019 06:53:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726828AbfBSGxv (ORCPT ); Tue, 19 Feb 2019 01:53:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39794 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725802AbfBSGxu (ORCPT ); Tue, 19 Feb 2019 01:53:50 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id BEE388666D; Tue, 19 Feb 2019 06:53:50 +0000 (UTC) Received: from jason-ThinkPad-T450s.redhat.com (ovpn-12-172.pek2.redhat.com [10.72.12.172]) by smtp.corp.redhat.com (Postfix) with ESMTP id 614F917B64; Tue, 19 Feb 2019 06:53:45 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net V2] vhost: correctly check the return value of translate_desc() in log_used() Date: Tue, 19 Feb 2019 14:53:44 +0800 Message-Id: <20190219065344.24923-1-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Tue, 19 Feb 2019 06:53:50 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When fail, translate_desc() returns negative value, otherwise the number of iovs. So we should fail when the return value is negative instead of a blindly check against zero. Detected by CoverityScan, CID# 1442593: Control flow issues (DEADCODE) Fixes: cc5e71075947 ("vhost: log dirty page correctly") Acked-by: Michael S. Tsirkin Reported-by: Stephen Hemminger Signed-off-by: Jason Wang --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 24a129fcdd61..a2e5dc7716e2 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1788,7 +1788,7 @@ static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len) ret = translate_desc(vq, (uintptr_t)vq->used + used_offset, len, iov, 64, VHOST_ACCESS_WO); - if (ret) + if (ret < 0) return ret; for (i = 0; i < ret; i++) { -- 2.17.1