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=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 68518C5ACAE for ; Wed, 11 Sep 2019 14:47:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A4F020863 for ; Wed, 11 Sep 2019 14:47:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728183AbfIKOr4 (ORCPT ); Wed, 11 Sep 2019 10:47:56 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:56910 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728181AbfIKOr4 (ORCPT ); Wed, 11 Sep 2019 10:47:56 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tonyk) with ESMTPSA id A9A02260785 From: =?UTF-8?q?Andr=C3=A9=20Almeida?= To: linux-block@vger.kernel.org, linux-doc@vger.kernel.org Cc: corbet@lwn.net, axboe@kernel.dk, m@bjorling.me, kernel@collabora.com, krisman@collabora.com, =?UTF-8?q?Andr=C3=A9=20Almeida?= Subject: [PATCH 3/3] null_blk: validated the number of devices Date: Wed, 11 Sep 2019 11:46:36 -0300 Message-Id: <20190911144636.226945-3-andrealmeid@collabora.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190911144636.226945-1-andrealmeid@collabora.com> References: <20190911144636.226945-1-andrealmeid@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org There is no sense defining a negative number of devices, so change the type to unsigned. If the number of devices is 0, it is impossible to the userspace interact with the module, so there is no reasoning in loading it. Signed-off-by: André Almeida --- drivers/block/null_blk_main.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index 7bc553ff7407..ab4b87677139 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -141,7 +141,7 @@ static int g_bs = 512; module_param_named(bs, g_bs, int, 0444); MODULE_PARM_DESC(bs, "Block size (in bytes)"); -static int nr_devices = 1; +static unsigned int nr_devices = 1; module_param(nr_devices, int, 0444); MODULE_PARM_DESC(nr_devices, "Number of devices to register"); @@ -1758,6 +1758,10 @@ static int __init null_init(void) pr_err("null_blk: legacy IO path no longer available\n"); return -EINVAL; } + if (!nr_devices) { + pr_err("null_blk: invalid number of devices\n"); + return -EINVAL; + } if (g_queue_mode == NULL_Q_MQ && g_use_per_node_hctx) { if (g_submit_queues != nr_online_nodes) { pr_warn("null_blk: submit_queues param is set to %u.\n", -- 2.23.0