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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6CFECC47086 for ; Tue, 12 Apr 2022 06:56:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351347AbiDLG6V (ORCPT ); Tue, 12 Apr 2022 02:58:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351693AbiDLGyM (ORCPT ); Tue, 12 Apr 2022 02:54:12 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BBAC381B8; Mon, 11 Apr 2022 23:43:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 90CEF6066C; Tue, 12 Apr 2022 06:43:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A93D3C385A1; Tue, 12 Apr 2022 06:43:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649745813; bh=1sLZ0yNT1HQT11YNTpxRT/Kai97X1dQ3iApND9rJu4w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BTfFCVStAgeg1Jc1iJztyWcLBNR3uHDUq89fG42Nvvn811gnXPCUEQqBCVGs9NTi0 xfR8U6tRwEprgtBmnYM0i44rkA7HoTRO/O6IbJNUqGFRQbvfaq8mOKOSoJzo05/YeP iTSwzcMSuWd8Js5rkT4cvlV5lrsKMqqrkef8RRFs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhang Wensheng , Josef Bacik , Jens Axboe , Sasha Levin Subject: [PATCH 5.15 007/277] nbd: fix possible overflow on first_minor in nbd_dev_add() Date: Tue, 12 Apr 2022 08:26:50 +0200 Message-Id: <20220412062942.244242820@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220412062942.022903016@linuxfoundation.org> References: <20220412062942.022903016@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhang Wensheng [ Upstream commit 6d35d04a9e18990040e87d2bbf72689252669d54 ] When 'index' is a big numbers, it may become negative which forced to 'int'. then 'index << part_shift' might overflow to a positive value that is not greater than '0xfffff', then sysfs might complains about duplicate creation. Because of this, move the 'index' judgment to the front will fix it and be better. Fixes: b0d9111a2d53 ("nbd: use an idr to keep track of nbd devices") Fixes: 940c264984fd ("nbd: fix possible overflow for 'first_minor' in nbd_dev_add()") Signed-off-by: Zhang Wensheng Reviewed-by: Josef Bacik Link: https://lore.kernel.org/r/20220310093224.4002895-1-zhangwensheng5@huawei.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/nbd.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 582b23befb5c..1c62262304be 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1744,17 +1744,6 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs) refcount_set(&nbd->refs, 0); INIT_LIST_HEAD(&nbd->list); disk->major = NBD_MAJOR; - - /* Too big first_minor can cause duplicate creation of - * 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 < index || disk->first_minor > MINORMASK) { - err = -EINVAL; - goto out_free_work; - } - disk->minors = 1 << part_shift; disk->fops = &nbd_fops; disk->private_data = nbd; @@ -1859,8 +1848,19 @@ static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info) if (!netlink_capable(skb, CAP_SYS_ADMIN)) return -EPERM; - if (info->attrs[NBD_ATTR_INDEX]) + if (info->attrs[NBD_ATTR_INDEX]) { index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]); + + /* + * Too big first_minor can cause duplicate creation of + * sysfs files/links, since index << part_shift might overflow, or + * MKDEV() expect that the max bits of first_minor is 20. + */ + if (index < 0 || index > MINORMASK >> part_shift) { + printk(KERN_ERR "nbd: illegal input index %d\n", index); + return -EINVAL; + } + } if (!info->attrs[NBD_ATTR_SOCKETS]) { printk(KERN_ERR "nbd: must specify at least one socket\n"); return -EINVAL; -- 2.35.1