From patchwork Thu Dec 26 08:15:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Sementsov-Ogievskiy X-Patchwork-Id: 1215448 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 47k2pW0Qcmz9sP3 for ; Thu, 26 Dec 2019 19:16:00 +1100 (AEDT) Received: from localhost ([::1]:51942 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ikOJI-0001kR-Ab for incoming@patchwork.ozlabs.org; Thu, 26 Dec 2019 03:15:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:39080) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ikOIv-0001k0-4G for qemu-devel@nongnu.org; Thu, 26 Dec 2019 03:15:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ikOIu-0001kC-2j for qemu-devel@nongnu.org; Thu, 26 Dec 2019 03:15:33 -0500 Received: from relay.sw.ru ([185.231.240.75]:33626) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ikOIr-0001ho-Cc; Thu, 26 Dec 2019 03:15:29 -0500 Received: from vovaso.qa.sw.ru ([10.94.3.0] helo=kvm.qa.sw.ru) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1ikOIk-0000kR-2r; Thu, 26 Dec 2019 11:15:22 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-block@nongnu.org Subject: [PATCH] nbd/server: improve nbd_negotiate_send_rep_list Date: Thu, 26 Dec 2019 11:15:21 +0300 Message-Id: <20191226081521.29652-1-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 185.231.240.75 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: vsementsov@virtuozzo.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Don't try to write zero-lenght strings. Signed-off-by: Vladimir Sementsov-Ogievskiy --- nbd/server.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/nbd/server.c b/nbd/server.c index 24ebc1a805..28a915f5a2 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -392,14 +392,18 @@ static int nbd_negotiate_send_rep_list(NBDClient *client, NBDExport *exp, return -EINVAL; } - if (nbd_write(ioc, name, name_len, errp) < 0) { - error_prepend(errp, "write failed (name buffer): "); - return -EINVAL; + if (name_len > 0) { + if (nbd_write(ioc, name, name_len, errp) < 0) { + error_prepend(errp, "write failed (name buffer): "); + return -EINVAL; + } } - if (nbd_write(ioc, desc, desc_len, errp) < 0) { - error_prepend(errp, "write failed (description buffer): "); - return -EINVAL; + if (desc_len > 0) { + if (nbd_write(ioc, desc, desc_len, errp) < 0) { + error_prepend(errp, "write failed (description buffer): "); + return -EINVAL; + } } return 0;