From patchwork Sun Oct 24 16:48:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Amir Mizinski X-Patchwork-Id: 12580339 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 DAAC6C433FE for ; Sun, 24 Oct 2021 16:52:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C7FF761051 for ; Sun, 24 Oct 2021 16:52:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231259AbhJXQyz (ORCPT ); Sun, 24 Oct 2021 12:54:55 -0400 Received: from 212.199.177.27.static.012.net.il ([212.199.177.27]:46229 "EHLO herzl.nuvoton.co.il" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S231534AbhJXQyz (ORCPT ); Sun, 24 Oct 2021 12:54:55 -0400 Received: from taln60.nuvoton.co.il (ntil-fw [212.199.177.25]) by herzl.nuvoton.co.il (8.13.8/8.13.8) with ESMTP id 19OGn56F004315; Sun, 24 Oct 2021 19:49:05 +0300 Received: by taln60.nuvoton.co.il (Postfix, from userid 10140) id CB5E963A20; Sun, 24 Oct 2021 19:49:16 +0300 (IDT) From: amirmizi6@gmail.com To: Eyal.Cohen@nuvoton.com, jarkko@kernel.org, oshrialkoby85@gmail.com, alexander.steffen@infineon.com, robh+dt@kernel.org, mark.rutland@arm.com, peterhuewe@gmx.de, jgg@ziepe.ca, arnd@arndb.de, gregkh@linuxfoundation.org, benoit.houyere@st.com, eajames@linux.ibm.com, joel@jms.id.au Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, oshri.alkoby@nuvoton.com, tmaimon77@gmail.com, gcwilson@us.ibm.com, kgoldman@us.ibm.com, Dan.Morav@nuvoton.com, oren.tanami@nuvoton.com, shmulik.hager@nuvoton.com, amir.mizinski@nuvoton.com, Amir Mizinski Subject: [PATCH v17 4/6] tpm: tpm_tis: Verify TPM_STS register is valid after locality request Date: Sun, 24 Oct 2021 19:48:53 +0300 Message-Id: <20211024164855.250362-5-amirmizi6@gmail.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20211024164855.250362-1-amirmizi6@gmail.com> References: <20211024164855.250362-1-amirmizi6@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Amir Mizinski This issue could occur when the TPM does not update TPM_STS register after a locality request (TPM_STS Initial value = 0xFF) and a TPM_STS register read occurs in the tpm_tis_status(chip) function call. When a call to tpm_tis_send_data() function is made after a request_locality() call, the condition ("if ((status & TPM_STS_COMMAND_READY) == 0)") is checked. At this moment if the status value is 0xFF, then it is considered, wrongly, in “ready” state (by checking only one bit). However, at this moment the TPM is, in fact, in "Idle" state and remains in "Idle" state because "tpm_tis_ready(chip);" was not executed. Waiting for the condition TPM_STS.tpmGo == 0, will ensure that the TPM status register has the correct value. Suggested-by: Benoit Houyere Signed-off-by: Amir Mizinski --- drivers/char/tpm/tpm_tis_core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index e1c4a5a..237b952 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -177,8 +177,14 @@ static int request_locality(struct tpm_chip *chip, int l) } else { /* wait for burstcount */ do { - if (check_locality(chip, l)) + if (check_locality(chip, l)) { + if (wait_for_tpm_stat(chip, TPM_STS_GO, 0, + chip->timeout_c, + &priv->int_queue, + false) < 0) + return -ETIME; return l; + } tpm_msleep(TPM_TIMEOUT); } while (time_before(jiffies, stop)); }