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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D132C433FE for ; Mon, 25 Oct 2021 17:05:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 87B1860F9D for ; Mon, 25 Oct 2021 17:05:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234955AbhJYRHg (ORCPT ); Mon, 25 Oct 2021 13:07:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:56224 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234799AbhJYREc (ORCPT ); Mon, 25 Oct 2021 13:04:32 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 33217610C8; Mon, 25 Oct 2021 17:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1635181295; bh=N4jTZEiCI/fgjQxxjR1nGSDTqF4wAhBvJtiTVgB91UM=; h=From:To:Cc:Subject:Date:From; b=mcfDnVD+Dpzl9H4spCwbTijo9wgf+WiZyIIN7BqgBDx73cHJHEL511VRdllQlIhJ6 M17ePP93azGets8Lg/OlawJX9XHYHfeSPcR7awCNeLUXxure11jW9om6O1Whwi7rwa PHA/1SGA19ZNTX2BElbY+9pmbi0sqq25UbayuFJMIyUCPejYIlnxYhoJqQ8WIcRrQt EtNGqeEyDuycoYooEqbLiO0ej3mUKDeiVwAGVb4ZUQ3XVzY3vK+Haj8PyG68aZmgNZ 50eqhEjWIAuax/kx6Buuns1PrCggMdw8z3E6KJ7ndLQcBc+jM0mm5fLq6QN4P8bKgp W4hhq2OFPehMg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ming Lei , Greg Kroah-Hartman , Changhui Zhong , Yi Zhang , "Martin K . Petersen" , Sasha Levin , jejb@linux.ibm.com, linux-scsi@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 1/4] scsi: core: Put LLD module refcnt after SCSI device is released Date: Mon, 25 Oct 2021 13:01:29 -0400 Message-Id: <20211025170132.1394887-1-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Ming Lei [ Upstream commit f2b85040acec9a928b4eb1b57a989324e8e38d3f ] SCSI host release is triggered when SCSI device is freed. We have to make sure that the low-level device driver module won't be unloaded before SCSI host instance is released because shost->hostt is required in the release handler. Make sure to put LLD module refcnt after SCSI device is released. Fixes a kernel panic of 'BUG: unable to handle page fault for address' reported by Changhui and Yi. Link: https://lore.kernel.org/r/20211008050118.1440686-1-ming.lei@redhat.com Cc: Greg Kroah-Hartman Reported-by: Changhui Zhong Reported-by: Yi Zhang Tested-by: Yi Zhang Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/scsi.c | 4 +++- drivers/scsi/scsi_sysfs.c | 9 +++++++++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 1deb6adc411f..4c9c1a8db8c3 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -951,8 +951,10 @@ EXPORT_SYMBOL(scsi_device_get); */ void scsi_device_put(struct scsi_device *sdev) { - module_put(sdev->host->hostt->module); + struct module *mod = sdev->host->hostt->module; + put_device(&sdev->sdev_gendev); + module_put(mod); } EXPORT_SYMBOL(scsi_device_put); diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 38830818bfb6..eae43a85e9b0 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -427,9 +427,12 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) struct device *parent; struct list_head *this, *tmp; unsigned long flags; + struct module *mod; sdev = container_of(work, struct scsi_device, ew.work); + mod = sdev->host->hostt->module; + scsi_dh_release_device(sdev); parent = sdev->sdev_gendev.parent; @@ -461,11 +464,17 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) if (parent) put_device(parent); + module_put(mod); } static void scsi_device_dev_release(struct device *dev) { struct scsi_device *sdp = to_scsi_device(dev); + + /* Set module pointer as NULL in case of module unloading */ + if (!try_module_get(sdp->host->hostt->module)) + sdp->host->hostt->module = NULL; + execute_in_process_context(scsi_device_dev_release_usercontext, &sdp->ew); } -- 2.33.0