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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83009C433EF for ; Thu, 21 Oct 2021 12:17:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 61F23610D0 for ; Thu, 21 Oct 2021 12:17:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230391AbhJUMUB (ORCPT ); Thu, 21 Oct 2021 08:20:01 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:29921 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231391AbhJUMSv (ORCPT ); Thu, 21 Oct 2021 08:18:51 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4HZmYq6ysxzbnKs; Thu, 21 Oct 2021 20:11:59 +0800 (CST) Received: from dggema762-chm.china.huawei.com (10.1.198.204) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.15; Thu, 21 Oct 2021 20:16:34 +0800 Received: from huawei.com (10.175.127.227) by dggema762-chm.china.huawei.com (10.1.198.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.15; Thu, 21 Oct 2021 20:16:33 +0800 From: Yu Kuai To: , , CC: , , , , , Subject: [PATCH 2/2] nbd: fix possible overflow for 'first_minor' in nbd_dev_add() Date: Thu, 21 Oct 2021 20:29:36 +0800 Message-ID: <20211021122936.758221-3-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211021122936.758221-1-yukuai3@huawei.com> References: <20211021122936.758221-1-yukuai3@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggema762-chm.china.huawei.com (10.1.198.204) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org If 'part_shift' is not zero, then 'index << part_shift' might overflow to a value that is not greater than '0xfffff', then sysfs might complains about duplicate creation. Fixes: b0d9111a2d53 ("nbd: use an idr to keep track of nbd devices") Signed-off-by: Yu Kuai --- drivers/block/nbd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 8f2c17a33c5b..03a10a87500d 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1808,11 +1808,11 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs) disk->major = NBD_MAJOR; /* Too big first_minor can cause duplicate creation of - * sysfs files/links, since MKDEV() expect that the max bits of - * first_minor is 20. + * sysfs files/links, since index << part_shift might overflow, or + * MKDEV() expect that the max bits of first_minor is 20. */ disk->first_minor = index << part_shift; - if (disk->first_minor > 0xfffff) { + if (disk->first_minor < index || disk->first_minor > 0xfffff) { err = -EINVAL; goto out_free_idr; } -- 2.31.1