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=-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 9667FC433E9 for ; Wed, 3 Feb 2021 13:21:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E7BD64E38 for ; Wed, 3 Feb 2021 13:21:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231493AbhBCNVH (ORCPT ); Wed, 3 Feb 2021 08:21:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231488AbhBCNVF (ORCPT ); Wed, 3 Feb 2021 08:21:05 -0500 Received: from mail-wr1-x434.google.com (mail-wr1-x434.google.com [IPv6:2a00:1450:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78DA1C0613D6 for ; Wed, 3 Feb 2021 05:20:25 -0800 (PST) Received: by mail-wr1-x434.google.com with SMTP id c4so21539027wru.9 for ; Wed, 03 Feb 2021 05:20:25 -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=Sjf5GlQNY1QkFhYOckMecV3FmqsRIYAFGfeVgRKIG/OoivLdo1rCyF07/AJmmohZY+ MKbHyrDktKZlxo0ycYetMdy4/Aj6zeaOv+NkJJj8XfWy0CUP4rNTHbVUouX/xeIQx1lk 9A0MScMEbgJUrsgGM5uNoRWxqdQJ/G7jAhIMdyd5LNQ9HcO8EQB0kmm6Sc4H370RXw7r tx5vMtuT2bgrP4aZTppQ5/xwHOp62yihD8gh/sHOaxfcuclinm7jJ6N37xn7tXWC81cn Cajx7Xx6q6i9q0ocFoN/mbxtu/jMYukCuz66EHwTHNzujfyG7NeyvyAZWZOQIS/DO+ie /5RQ== 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=eWcx8n3MpRl8UqMSYKO+WnZN2I0LwCpItHMQfIFgHdBYNPPK0unYqkSMTNoa+FL8x9 LcgGH2sxZQ/lNZgPYwX+ROQaJlU8zCny5xGUgY3P030MOTT82MUfx6YR+hnQU8zbo2ew m8UtAfY+ZKS7CNtXMKam0+ctiBE4LZqTfBpMj/VrtULaky++Fs1EuKtlc0nnfwYzq8Gf vPNgMaWix2N1rwyZPGJkiTFCvzjAk1uX5DR3aYs/rU5j/2EJhO/bVTr6+QRngReYkvxz 9CwtgQsKNw+W+x7Oc7QZz9d6qVi0w1ktWyY39yXqkKXZ3BJ6OrX6FLr/J2UepxALO0sY G3uQ== X-Gm-Message-State: AOAM531nXvDjLIYqcA/5S6hR0TpWeqHpB2e/J2FpsX0iO7kCrrNF+TZ3 E1pFufHvivXX2R+lvpsB9CNZ0up6bMQr7Q== X-Google-Smtp-Source: ABdhPJxEv8Hb+n7xGjimcxlgQepVL4lqiOf2Hz6h/HZ988L7BcMKjam5+5nDlfdlarLuhAhjj/I2Jw== X-Received: by 2002:adf:dd0d:: with SMTP id a13mr3514589wrm.143.1612358424285; Wed, 03 Feb 2021 05:20:24 -0800 (PST) Received: from jwang-Latitude-5491.fritz.box ([2001:16b8:4947:3c00:7cf4:7472:391:9d0d]) by smtp.gmail.com with ESMTPSA id d10sm3738430wrn.88.2021.02.03.05.20.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Feb 2021 05:20:23 -0800 (PST) From: Jack Wang To: gregkh@linuxfoundation.org, sashal@kernel.org, stable@vger.kernel.org Cc: zhengbin , Jens Axboe Subject: [stable-4.19 1/8] block: fix NULL pointer dereference in register_disk Date: Wed, 3 Feb 2021 14:20:15 +0100 Message-Id: <20210203132022.92406-2-jinpu.wang@cloud.ionos.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210203132022.92406-1-jinpu.wang@cloud.ionos.com> References: <20210203132022.92406-1-jinpu.wang@cloud.ionos.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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); + } } /** -- 2.25.1