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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 858D5C433FE for ; Wed, 9 Dec 2020 21:35:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A64123B51 for ; Wed, 9 Dec 2020 21:35:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388165AbgLIVeZ (ORCPT ); Wed, 9 Dec 2020 16:34:25 -0500 Received: from mx2.suse.de ([195.135.220.15]:34018 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388045AbgLIVeY (ORCPT ); Wed, 9 Dec 2020 16:34:24 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 74ACFACE1; Wed, 9 Dec 2020 21:33:36 +0000 (UTC) From: Enzo Matsumiya To: linux-nvme@lists.infradead.org Cc: Enzo Matsumiya , Keith Busch , Jens Axboe , Christoph Hellwig , Sagi Grimberg , linux-kernel@vger.kernel.org Subject: [PATCH] nvme: hwmon: fix crash on device teardown Date: Wed, 9 Dec 2020 18:32:27 -0300 Message-Id: <20201209213228.5044-1-ematsumiya@suse.de> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fix a possible NULL pointer dereference when trying to read hwmon sysfs entries associated to NVMe-oF devices that were hot-removed or disconnected. Unregister the NVMe hwmon device upon controller teardown (nvme_stop_ctrl()). Signed-off-by: Enzo Matsumiya --- drivers/nvme/host/core.c | 1 + drivers/nvme/host/hwmon.c | 8 ++++++++ drivers/nvme/host/nvme.h | 2 ++ 3 files changed, 11 insertions(+) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 9a270e49df17..becc80a0c3b8 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -4344,6 +4344,7 @@ EXPORT_SYMBOL_GPL(nvme_complete_async_event); void nvme_stop_ctrl(struct nvme_ctrl *ctrl) { + nvme_hwmon_exit(ctrl); nvme_mpath_stop(ctrl); nvme_stop_keep_alive(ctrl); flush_work(&ctrl->async_event_work); diff --git a/drivers/nvme/host/hwmon.c b/drivers/nvme/host/hwmon.c index 552dbc04567b..7f62cca4c577 100644 --- a/drivers/nvme/host/hwmon.c +++ b/drivers/nvme/host/hwmon.c @@ -71,6 +71,9 @@ static int nvme_hwmon_read(struct device *dev, enum hwmon_sensor_types type, int temp; int err; + if (data->ctrl->state != NVME_CTRL_LIVE) + return -EAGAIN; + /* * First handle attributes which don't require us to read * the smart log. @@ -253,3 +256,8 @@ int nvme_hwmon_init(struct nvme_ctrl *ctrl) return 0; } + +void nvme_hwmon_exit(struct nvme_ctrl *ctrl) +{ + hwmon_device_unregister(ctrl->dev); +} diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 567f7ad18a91..621e9b1575f6 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -807,11 +807,13 @@ static inline struct nvme_ns *nvme_get_ns_from_dev(struct device *dev) #ifdef CONFIG_NVME_HWMON int nvme_hwmon_init(struct nvme_ctrl *ctrl); +void nvme_hwmon_exit(struct nvme_ctrl *ctrl); #else static inline int nvme_hwmon_init(struct nvme_ctrl *ctrl) { return 0; } +static inline void nvme_hwmon_exit(struct nvme_ctrl *ctrl) { } #endif u32 nvme_command_effects(struct nvme_ctrl *ctrl, struct nvme_ns *ns, -- 2.29.2