From patchwork Tue Jan 7 22:04:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tadeusz Struk X-Patchwork-Id: 1176682 Return-Path: Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5846CC3F68F for ; Tue, 7 Jan 2020 22:04:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 207982073D for ; Tue, 7 Jan 2020 22:04:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727451AbgAGWEl (ORCPT ); Tue, 7 Jan 2020 17:04:41 -0500 Received: from mga11.intel.com ([192.55.52.93]:40523 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727080AbgAGWEk (ORCPT ); Tue, 7 Jan 2020 17:04:40 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Jan 2020 14:04:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,407,1571727600"; d="scan'208";a="217317989" Received: from tstruk-mobl1.jf.intel.com (HELO [127.0.1.1]) ([10.7.196.67]) by fmsmga007.fm.intel.com with ESMTP; 07 Jan 2020 14:04:39 -0800 Subject: [PATCH] tpm: handle negative priv->response_len in tpm_common_read From: Tadeusz Struk To: jarkko.sakkinen@linux.intel.com Cc: keescook@chromium.org, tadeusz.struk@intel.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-integrity@vger.kernel.org, labbott@redhat.com Date: Tue, 07 Jan 2020 14:04:48 -0800 Message-ID: <157843468820.24718.10808226634364669421.stgit@tstruk-mobl1> In-Reply-To: References: User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The priv->responce_length can hold the size of an response or an negative error code, and the tpm_common_read() needs to handle both cases correctly. Changed the type of responce_length to signed and accounted for negative value in tpm_common_read() Cc: stable@vger.kernel.org Fixes: d23d12484307 ("tpm: fix invalid locking in NONBLOCKING mode") Reported-by: Laura Abbott Signed-off-by: Tadeusz Struk Reviewed-by: Jarkko Sakkinen --- drivers/char/tpm/tpm-dev-common.c | 2 +- drivers/char/tpm/tpm-dev.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c index b23b0b999232..87f449340202 100644 --- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c @@ -130,7 +130,7 @@ ssize_t tpm_common_read(struct file *file, char __user *buf, priv->response_read = true; ret_size = min_t(ssize_t, size, priv->response_length); - if (!ret_size) { + if (ret_size <= 0) { priv->response_length = 0; goto out; } diff --git a/drivers/char/tpm/tpm-dev.h b/drivers/char/tpm/tpm-dev.h index 1089fc0bb290..f3742bcc73e3 100644 --- a/drivers/char/tpm/tpm-dev.h +++ b/drivers/char/tpm/tpm-dev.h @@ -14,7 +14,7 @@ struct file_priv { struct work_struct timeout_work; struct work_struct async_work; wait_queue_head_t async_wait; - size_t response_length; + ssize_t response_length; bool response_read; bool command_enqueued;