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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 B23F1C43603 for ; Thu, 12 Dec 2019 17:48:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F0F42067C for ; Thu, 12 Dec 2019 17:48:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730205AbfLLRsq (ORCPT ); Thu, 12 Dec 2019 12:48:46 -0500 Received: from mga11.intel.com ([192.55.52.93]:42295 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729771AbfLLRsp (ORCPT ); Thu, 12 Dec 2019 12:48:45 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Dec 2019 09:48:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,306,1571727600"; d="scan'208";a="414006006" Received: from tstruk-mobl1.jf.intel.com (HELO [127.0.1.1]) ([10.7.196.67]) by fmsmga005.fm.intel.com with ESMTP; 12 Dec 2019 09:48:44 -0800 Subject: [PATCH =v2 1/3] tpm: fix invalid locking in NONBLOCKING mode From: Tadeusz Struk To: jarkko.sakkinen@linux.intel.com Cc: tadeusz.struk@intel.com, peterz@infradead.org, linux-kernel@vger.kernel.org, jgg@ziepe.ca, mingo@redhat.com, jeffrin@rajagiritech.edu.in, linux-integrity@vger.kernel.org, will@kernel.org, peterhuewe@gmx.de Date: Thu, 12 Dec 2019 09:48:47 -0800 Message-ID: <157617292787.8172.9586296287013438621.stgit@tstruk-mobl1> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When an application sends TPM commands in NONBLOCKING mode the driver holds chip->tpm_mutex returning from write(), which triggers: "WARNING: lock held when returning to user space". To fix this issue the driver needs to release the mutex before returning and acquire it again in tpm_dev_async_work() before sending the command. Cc: stable@vger.kernel.org Fixes: 9e1b74a63f776 (tpm: add support for nonblocking operation) Reported-by: Jeffrin Jose T Tested-by: Jeffrin Jose T Signed-off-by: Tadeusz Struk --- Changes in v2: - Updated commit message as requested - Add the fix and test updates to the same series --- drivers/char/tpm/tpm-dev-common.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c index 2ec47a69a2a6..b23b0b999232 100644 --- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c @@ -61,6 +61,12 @@ static void tpm_dev_async_work(struct work_struct *work) mutex_lock(&priv->buffer_mutex); priv->command_enqueued = false; + ret = tpm_try_get_ops(priv->chip); + if (ret) { + priv->response_length = ret; + goto out; + } + ret = tpm_dev_transmit(priv->chip, priv->space, priv->data_buffer, sizeof(priv->data_buffer)); tpm_put_ops(priv->chip); @@ -68,6 +74,7 @@ static void tpm_dev_async_work(struct work_struct *work) priv->response_length = ret; mod_timer(&priv->user_read_timer, jiffies + (120 * HZ)); } +out: mutex_unlock(&priv->buffer_mutex); wake_up_interruptible(&priv->async_wait); } @@ -204,6 +211,7 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf, if (file->f_flags & O_NONBLOCK) { priv->command_enqueued = true; queue_work(tpm_dev_wq, &priv->async_work); + tpm_put_ops(priv->chip); mutex_unlock(&priv->buffer_mutex); return size; }