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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 C1AB2C43381 for ; Thu, 21 Feb 2019 14:39:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F15D2085A for ; Thu, 21 Feb 2019 14:39:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550759952; bh=SxA3hF+51Q+Ykf6fzx6P1+/pxHLlsr0NraTH3t6OZeU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Bia7e4CSb6DYCHWKxARGsN0uS1+lB7QvRO7E+o2n4yuDgUI11SlFlBj8lxdtUjvd1 KwueqE7VxYy4NmXZDlHitQ7KOcgp8gwyoMuBPldWESgJjmE+S2A81NgtVJQsoUXILN yjiovGq4xuu/50hwHuqrr1mAjKLh75EHZljgXzrU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728822AbfBUOjL (ORCPT ); Thu, 21 Feb 2019 09:39:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:32862 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728804AbfBUOjF (ORCPT ); Thu, 21 Feb 2019 09:39:05 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 936CE2080D; Thu, 21 Feb 2019 14:39:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550759945; bh=SxA3hF+51Q+Ykf6fzx6P1+/pxHLlsr0NraTH3t6OZeU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZuPucBDvY7JrPU9yuWFZGBLXCv7FZAwUd1P1arGc3Kq0Y3SW/eLTFBHTNQPt5vwih Ma1vEj0z7NqQaQnGy7HbhO6vJgj8+VB279eHehWihhPvGmK833Z1m7iDE9d1vTHYov 7O3w15wbh9t981B3mvoRQyxXOmH0jdFxgGMMbZQA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Michael S. Tsirkin" , Stephen Hemminger , Jason Wang , "David S. Miller" Subject: [PATCH 4.9 09/20] vhost: correctly check the return value of translate_desc() in log_used() Date: Thu, 21 Feb 2019 15:35:47 +0100 Message-Id: <20190221125243.337559115@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190221125242.153179182@linuxfoundation.org> References: <20190221125242.153179182@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang [ Upstream commit 816db7663565cd23f74ed3d5c9240522e3fb0dda ] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1696,7 +1696,7 @@ static int log_used(struct vhost_virtque 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++) {