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 A3AABC64ED6 for ; Thu, 23 Feb 2023 13:13:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234479AbjBWNNr (ORCPT ); Thu, 23 Feb 2023 08:13:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234545AbjBWNNk (ORCPT ); Thu, 23 Feb 2023 08:13:40 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B798157088 for ; Thu, 23 Feb 2023 05:13:17 -0800 (PST) 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 047B461707 for ; Thu, 23 Feb 2023 13:12:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C71D0C4339B; Thu, 23 Feb 2023 13:12:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1677157959; bh=h3xdzdm2ysYKzw3NFWnpywmjvcdoHl7sU+zSiHj7Oak=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VOQayRn7+SQGSaHfWBTEdoGmzto34HKFJxHxmU7phUbY6KMZIZYbMGpPWPZDJ6eS8 Q46tNxI+cYjBKSNE8DT2iid8Bz3bu0aurXaJ9yOzCg1aE6M+osc5+U2F6YUxwec01G HATKwxhXe2tMPAKYUaxNX/aGCX/7OagO4D299nhU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhang Wensheng , Yu Kuai , Josef Bacik , Jens Axboe , Wen Yang Subject: [PATCH 5.15 28/36] nbd: fix possible overflow on first_minor in nbd_dev_add() Date: Thu, 23 Feb 2023 14:07:04 +0100 Message-Id: <20230223130430.370121519@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230223130429.072633724@linuxfoundation.org> References: <20230223130429.072633724@linuxfoundation.org> User-Agent: quilt/0.67 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 commit 858f1bf65d3d9c00b5e2d8ca87dc79ed88267c98 upstream. 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 Signed-off-by: Yu Kuai Reviewed-by: Josef Bacik Link: https://lore.kernel.org/r/20220521073749.3146892-6-yukuai3@huawei.com Signed-off-by: Jens Axboe Signed-off-by: Wen Yang Signed-off-by: Greg Kroah-Hartman --- drivers/block/nbd.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1756,17 +1756,7 @@ static struct nbd_device *nbd_dev_add(in 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; @@ -1871,8 +1861,19 @@ static int nbd_genl_connect(struct sk_bu 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;