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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 8DADAC43381 for ; Wed, 13 Jan 2021 14:54:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 457D523358 for ; Wed, 13 Jan 2021 14:54:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727726AbhAMOyU (ORCPT ); Wed, 13 Jan 2021 09:54:20 -0500 Received: from mga07.intel.com ([134.134.136.100]:53443 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727041AbhAMOyP (ORCPT ); Wed, 13 Jan 2021 09:54:15 -0500 IronPort-SDR: fxRouFCrlRLTzqU1GvSXi2yReE8qK38AfldbKQIMpA0HxbTellqNgBdV2o44Gbo1JRAi7oMKRI eu2djEfgh/cw== X-IronPort-AV: E=McAfee;i="6000,8403,9862"; a="242288236" X-IronPort-AV: E=Sophos;i="5.79,344,1602572400"; d="scan'208";a="242288236" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jan 2021 06:53:34 -0800 IronPort-SDR: HzcL5yAEpBEgCs+I1a3Zyi5Mnl2vl1gGIreeiUkOSjuip/oBB8/sf2Kxd+FjwuXfwLRcW93BGq vCRseHr1fwrA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.79,344,1602572400"; d="scan'208";a="464925238" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.149]) ([10.237.72.149]) by fmsmga001.fm.intel.com with ESMTP; 13 Jan 2021 06:53:29 -0800 Subject: Re: [PATCH v4 2/2] scsi: ufs: Protect PM ops and err_handler from user access through sysfs To: Can Guo , asutoshd@codeaurora.org, nguyenb@codeaurora.org, hongwus@codeaurora.org, rnayak@codeaurora.org, linux-scsi@vger.kernel.org, kernel-team@android.com, saravanak@google.com, salyzyn@google.com Cc: Alim Akhtar , Avri Altman , "James E.J. Bottomley" , "Martin K. Petersen" , Matthias Brugger , Stanley Chu , Bean Huo , Nitin Rawat , Satya Tangirala , open list , "moderated list:ARM/Mediatek SoC support" , "moderated list:ARM/Mediatek SoC support" References: <1610546230-14732-1-git-send-email-cang@codeaurora.org> <1610546230-14732-3-git-send-email-cang@codeaurora.org> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: Date: Wed, 13 Jan 2021 16:53:28 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <1610546230-14732-3-git-send-email-cang@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13/01/21 3:57 pm, Can Guo wrote: > User layer may access sysfs nodes when system PM ops or error handling > is running, which can cause various problems. Rename eh_sem to host_sem > and use it to protect PM ops and error handling from user layer intervene. > > Acked-by: Avri Altman > Reviewed-by: Stanley Chu > Signed-off-by: Can Guo > --- > drivers/scsi/ufs/ufs-sysfs.c | 106 ++++++++++++++++++++++++++++++++++++------- > drivers/scsi/ufs/ufshcd.c | 42 ++++++++++------- > drivers/scsi/ufs/ufshcd.h | 10 +++- > 3 files changed, 125 insertions(+), 33 deletions(-) > > diff --git a/drivers/scsi/ufs/ufs-sysfs.c b/drivers/scsi/ufs/ufs-sysfs.c > index 0e14384..7cafffc 100644 > --- a/drivers/scsi/ufs/ufs-sysfs.c > +++ b/drivers/scsi/ufs/ufs-sysfs.c > @@ -154,18 +154,29 @@ static ssize_t auto_hibern8_show(struct device *dev, > struct device_attribute *attr, char *buf) > { > u32 ahit; > + int ret; > struct ufs_hba *hba = dev_get_drvdata(dev); > > if (!ufshcd_is_auto_hibern8_supported(hba)) > return -EOPNOTSUPP; > > + down(&hba->host_sem); > + if (!ufshcd_is_sysfs_allowed(hba)) { I expect debugfs has the same potential problem, so maybe ufshcd_is_sysfs_allowed() is not quite the right name. > + ret = -EBUSY; > + goto out; > + } > +