From patchwork Mon Feb 8 15:04:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jinpu Wang X-Patchwork-Id: 379264 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 87AC7C433DB for ; Mon, 8 Feb 2021 15:07:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 441B664ED4 for ; Mon, 8 Feb 2021 15:07:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231754AbhBHPGw (ORCPT ); Mon, 8 Feb 2021 10:06:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232753AbhBHPFJ (ORCPT ); Mon, 8 Feb 2021 10:05:09 -0500 Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B18AC061788 for ; Mon, 8 Feb 2021 07:04:29 -0800 (PST) Received: by mail-ed1-x52e.google.com with SMTP id c6so18527511ede.0 for ; Mon, 08 Feb 2021 07:04:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloud.ionos.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Od4EK2yVIIkurXebLowbqftTipY7/kgNJZJogZrgQvQ=; b=gkWsleFufxbYGB31Xpuu3Ew0nmDJL2dPT1dQQHXNVjmAkTGyrTUsWEHNSK5wfRM0Mh o3nJ5HrA+GWWMRG2sNpRNYzhlqrOgnFub2loCMYIxgIutz5mUKnWLbcn+AwQhQJO/oHz ibrkjJzcY+ljr4aT7cid5A5ds1gDEwlYvDnhWCnwG5elg8BtD/C6G5ng+UuoJz7pvysc BxkmcmqUbveDsv5YKnWlq0IxW5gGWJ4aF0/3a4YFzgJKI+BwhFsvZ4vFyq7IGe93FEby RVjkIotPjo5moHFMo49X4sUUmmsRtDCD16HRhNv7zrIVddbr7BfQbIToMk/F8uGBq9T5 W58A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Od4EK2yVIIkurXebLowbqftTipY7/kgNJZJogZrgQvQ=; b=Eq+hOWXYeePTdui0CnigGQZCfutXXNdR/p+ybD94CgW47JBv5kOXlhkZXdYU4kuJB8 sNEG1qF0n8gbp2793hmZZFVzCepzql1ENqM1DaeCSYo8WPkrrtYuOYzHjzrBEIg70JKy 6Ra1qcNvBV4MwPOOkwV0LrjFhMlThvQvWyVxwVNJqTDDHl01MuaoTN4zeod98O3FtaL3 Rp5n9mKwa6XIRecKdjbBhxMY1T5P5EUy276S3nD6b4Uj1N0pUtVlL+FOO8D9TiGgfhVo U/QBWEQlOjaX1fdvlHVCIaZhtwTbBZEBSODPwL8piWcqd8Xz/fg0nsbgNyLHqxqDvpGQ k84w== X-Gm-Message-State: AOAM533TcFy26iOUZv5awY1V2iThke5vpdf0rJo+6M+ChPCjXzCbsp4m 88t1RQcfQCW8rdg/ydNNZiAZLg== X-Google-Smtp-Source: ABdhPJwWlt27fiCNOFgDFZNVVmnLRQYaoTdbsi115S0r+YDG7ugxftMDPK/WsB4QYCu2e0rMPdHn6A== X-Received: by 2002:a05:6402:b27:: with SMTP id bo7mr17358079edb.372.1612796668173; Mon, 08 Feb 2021 07:04:28 -0800 (PST) Received: from jwang-Latitude-5491.fkb.profitbricks.net ([2001:16b8:4980:d900:bc0f:acd:c20a:c261]) by smtp.gmail.com with ESMTPSA id kb25sm4359106ejc.19.2021.02.08.07.04.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Feb 2021 07:04:27 -0800 (PST) From: Jack Wang To: gregkh@linuxfoundation.org, sashal@kernel.org, axboe@kernel.dk, stable@vger.kernel.org Cc: zhengbin Subject: [stable-4.19 Resend 1/7] block: fix NULL pointer dereference in register_disk Date: Mon, 8 Feb 2021 16:04:20 +0100 Message-Id: <20210208150426.62755-2-jinpu.wang@cloud.ionos.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210208150426.62755-1-jinpu.wang@cloud.ionos.com> References: <20210208150426.62755-1-jinpu.wang@cloud.ionos.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: zhengbin If __device_add_disk-->bdi_register_owner-->bdi_register--> bdi_register_va-->device_create_vargs fails, bdi->dev is still NULL, __device_add_disk-->register_disk will visit bdi->dev->kobj. This patch fixes that. Signed-off-by: zhengbin Signed-off-by: Jens Axboe (cherry picked from commit 4d7c1d3fd7c7eda7dea351f071945e843a46c145) Signed-off-by: Jack Wang --- block/genhd.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 2b536ab570ac..6965dde96373 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -652,10 +652,12 @@ static void register_disk(struct device *parent, struct gendisk *disk) kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD); disk_part_iter_exit(&piter); - err = sysfs_create_link(&ddev->kobj, - &disk->queue->backing_dev_info->dev->kobj, - "bdi"); - WARN_ON(err); + if (disk->queue->backing_dev_info->dev) { + err = sysfs_create_link(&ddev->kobj, + &disk->queue->backing_dev_info->dev->kobj, + "bdi"); + WARN_ON(err); + } } /**