From patchwork Thu Dec 6 17:58:01 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Steffen X-Patchwork-Id: 10716543 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 83C4817D5 for ; Thu, 6 Dec 2018 18:08:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 711032E06C for ; Thu, 6 Dec 2018 18:08:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6282B2F0A1; Thu, 6 Dec 2018 18:08:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CBB4C2E06C for ; Thu, 6 Dec 2018 18:07:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726044AbeLFSHz (ORCPT ); Thu, 6 Dec 2018 13:07:55 -0500 Received: from mail.dice.at ([217.10.52.18]:29916 "EHLO smtp2.infineon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726045AbeLFSHz (ORCPT ); Thu, 6 Dec 2018 13:07:55 -0500 X-Greylist: delayed 583 seconds by postgrey-1.27 at vger.kernel.org; Thu, 06 Dec 2018 13:07:53 EST DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infineon.com; i=@infineon.com; q=dns/txt; s=IFXMAIL; t=1544119699; x=1575655699; h=from:to:cc:subject:date:message-id:mime-version; bh=Vj11rthUJOzzcJQez56EA0KjttwsIJa2K86w87xVAWA=; b=RzpUaCjdjQqIoUxJ84AHn3cZDamVLk19CFBgpCKJzQTWJ2n3xAuFM8YM 6+Ai5KSDwY+LPfb+LRbKBVhm9P1a89SVBckZqo6q3/QNPvzhfXzupU6pt +Xw+F0FKmi1o2UfQv1M/aQErCjdYS9S+mAjamumvPSeFtt7+MC7s+6Cz5 E=; X-SBRS: None X-IronPort-AV: E=McAfee;i="5900,7806,9099"; a="91670674" X-IronPort-AV: E=Sophos;i="5.56,323,1539640800"; d="scan'208";a="91670674" Received: from unknown (HELO mucxv002.muc.infineon.com) ([172.23.11.17]) by smtp2.infineon.com with ESMTP/TLS/AES256-GCM-SHA384; 06 Dec 2018 18:58:34 +0100 Received: from MUCSE708.infineon.com (MUCSE708.infineon.com [172.23.7.82]) by mucxv002.muc.infineon.com (Postfix) with ESMTPS; Thu, 6 Dec 2018 18:58:09 +0100 (CET) Received: from ISCNPC0VBFBX.infineon.com (172.23.8.247) by MUCSE708.infineon.com (172.23.7.82) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P256) id 15.1.1531.3; Thu, 6 Dec 2018 18:58:08 +0100 From: Alexander Steffen To: Jarkko Sakkinen , Tadeusz Struk CC: , , , , Alexander Steffen Subject: [PATCH] tpm-dev: Require response to be read only if there actually is a response Date: Thu, 6 Dec 2018 18:58:01 +0100 Message-ID: <20181206175801.23048-1-Alexander.Steffen@infineon.com> X-Mailer: git-send-email 2.18.0.windows.1 MIME-Version: 1.0 X-Originating-IP: [172.23.8.247] X-ClientProxiedBy: MUCSE713.infineon.com (172.23.7.71) To MUCSE708.infineon.com (172.23.7.82) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP If the tpm_transmit call in tpm_common_write fails for any reason, there is no response that could be read. Therefore, do not require the application to issue a read call before sending further commands. This restores the behavior from before support for partial reads was introduced. Signed-off-by: Alexander Steffen --- Feel free to merge this into Tadeusz' original commit. drivers/char/tpm/tpm-dev-common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c index 344739223451..5eecad233ea1 100644 --- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c @@ -140,7 +140,8 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf, * tpm_read or a user_read_timer timeout. This also prevents split * buffered writes from blocking here. */ - if (!priv->response_read || priv->command_enqueued) { + if ((!priv->response_read && priv->response_length) || + priv->command_enqueued) { ret = -EBUSY; goto out; }