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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 F090FC433E0 for ; Tue, 7 Jul 2020 15:19:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C104C2065D for ; Tue, 7 Jul 2020 15:19:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594135154; bh=SOHD4JQllf3nDabfdNkDslA68fyYTjsdIl+3w4uFs6c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KgrL5X26gCinol/Sa1ZovN798RnzhccIs7OfDKghXHpVn9AdvERlOhES+id1sdVTy a7oNB1eq3eXMJJ9wWHy5Nmn69kFoBadAJ/Ot9mi8rDdGiML7j450od32yYbsM8jtQm bDmb557KD/TSTGgBqcLQ6iqFTbRUpYKotXoSAMgw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729300AbgGGPTO (ORCPT ); Tue, 7 Jul 2020 11:19:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:58880 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728714AbgGGPTN (ORCPT ); Tue, 7 Jul 2020 11:19:13 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5D9D220674; Tue, 7 Jul 2020 15:19:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594135152; bh=SOHD4JQllf3nDabfdNkDslA68fyYTjsdIl+3w4uFs6c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oNUfkpuryc0kvcgi6P2uumr6LiKCCPHMTTRoa5cSYLA1AuplVoNPyqfauQ1Mgesfk f98PiJneA95TDFO43K5HcZ7xGdEkzrpU2yPyEucJPrtsIXqU7K1rHjTc/CfhHtlt56 ammJ6avmo7Tikus/5tJvE7IAuNC5B2zKZvjn4Jeg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Avinash M N , Christoph Hellwig , Sagi Grimberg , Max Gurtovoy , Sasha Levin Subject: [PATCH 4.19 24/36] nvme: fix a crash in nvme_mpath_add_disk Date: Tue, 7 Jul 2020 17:17:16 +0200 Message-Id: <20200707145750.283893884@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707145749.130272978@linuxfoundation.org> References: <20200707145749.130272978@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Christoph Hellwig [ Upstream commit 72d447113bb751ded97b2e2c38f886e4a4139082 ] For private namespaces ns->head_disk is NULL, so add a NULL check before updating the BDI capabilities. Fixes: b2ce4d90690b ("nvme-multipath: set bdi capabilities once") Reported-by: Avinash M N Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Max Gurtovoy Signed-off-by: Sasha Levin --- drivers/nvme/host/multipath.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 3ad6183c5e6b4..2e63c1106030b 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -532,10 +532,11 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id) } if (bdi_cap_stable_pages_required(ns->queue->backing_dev_info)) { - struct backing_dev_info *info = - ns->head->disk->queue->backing_dev_info; + struct gendisk *disk = ns->head->disk; - info->capabilities |= BDI_CAP_STABLE_WRITES; + if (disk) + disk->queue->backing_dev_info->capabilities |= + BDI_CAP_STABLE_WRITES; } } -- 2.25.1