From patchwork Fri Jul 19 15:03:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 11050269 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1261913BD for ; Fri, 19 Jul 2019 15:26:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F41E728821 for ; Fri, 19 Jul 2019 15:26:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E7F0028892; Fri, 19 Jul 2019 15:26:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5C5DA28821 for ; Fri, 19 Jul 2019 15:26:58 +0000 (UTC) Received: from localhost ([::1]:46258 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hoUmf-0005KE-PN for patchwork-qemu-devel@patchwork.kernel.org; Fri, 19 Jul 2019 11:26:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60096) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hoUmY-0004vT-1b for qemu-devel@nongnu.org; Fri, 19 Jul 2019 11:26:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hoUmU-0004Vd-Bh for qemu-devel@nongnu.org; Fri, 19 Jul 2019 11:26:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40185) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hoUmF-0002PC-2P; Fri, 19 Jul 2019 11:26:34 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 936BE30B9912; Fri, 19 Jul 2019 15:03:19 +0000 (UTC) Received: from blue.redhat.com (ovpn-116-46.phx2.redhat.com [10.3.116.46]) by smtp.corp.redhat.com (Postfix) with ESMTP id ED3BA1001B14; Fri, 19 Jul 2019 15:03:18 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Date: Fri, 19 Jul 2019 10:03:13 -0500 Message-Id: <20190719150313.29198-1-eblake@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Fri, 19 Jul 2019 15:03:19 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] nbd: Initialize reply on failure X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Andrey Shinkevich , Thomas Huth , "open list:Network Block Dev..." , Max Reitz Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP We've had two separate reports of a caller running into use of uninitialized data if s->quit is set (one detected by gcc -O3, another by valgrind), due to checking 'nbd_reply_is_simple(reply) || s->quit' in the wrong order. Rather than chasing down which callers need to pre-initialize reply, it's easier to guarantee that reply will always be set by nbd_co_receive_one_chunk() even on failure. Reported-by: Thomas Huth Reported-by: Andrey Shinkevich Signed-off-by: Eric Blake Reviewed-by: Andrey Shinkevich Reviewed-by: Philippe Mathieu-Daudé --- Replaces: https://lists.gnu.org/archive/html/qemu-devel/2019-07/msg04477.html Replaces: https://lists.gnu.org/archive/html/qemu-devel/2019-07/msg03712.html block/nbd.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/nbd.c b/block/nbd.c index 8d565cc624ec..f751a8e633e5 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -640,6 +640,7 @@ static coroutine_fn int nbd_co_receive_one_chunk( request_ret, qiov, payload, errp); if (ret < 0) { + memset(reply, 0, sizeof *reply); s->quit = true; } else { /* For assert at loop start in nbd_connection_entry */