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=-13.7 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 7B326C43217 for ; Tue, 14 Sep 2021 15:13:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65E966112D for ; Tue, 14 Sep 2021 15:13:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234255AbhINPOr (ORCPT ); Tue, 14 Sep 2021 11:14:47 -0400 Received: from 212.199.177.27.static.012.net.il ([212.199.177.27]:43285 "EHLO herzl.nuvoton.co.il" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S234151AbhINPOk (ORCPT ); Tue, 14 Sep 2021 11:14:40 -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 18EFAmXl031450; Tue, 14 Sep 2021 18:10:48 +0300 Received: by taln60.nuvoton.co.il (Postfix, from userid 10140) id 2FF7263A19; Tue, 14 Sep 2021 18:10:59 +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 v15 4/6] tpm: tpm_tis: verify TPM_STS register is valid after locality request Date: Tue, 14 Sep 2021 18:10:30 +0300 Message-Id: <20210914151032.216122-5-amirmizi6@gmail.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20210914151032.216122-1-amirmizi6@gmail.com> References: <20210914151032.216122-1-amirmizi6@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 7ea7f64..f340a44 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)); } -- 2.7.4