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,URIBL_BLOCKED,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 7A9A2C433F5 for ; Mon, 13 Sep 2021 14:50:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 652FC60F8F for ; Mon, 13 Sep 2021 14:50:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346626AbhIMOvm (ORCPT ); Mon, 13 Sep 2021 10:51:42 -0400 Received: from 212.199.177.27.static.012.net.il ([212.199.177.27]:42989 "EHLO herzl.nuvoton.co.il" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1347133AbhIMOsY (ORCPT ); Mon, 13 Sep 2021 10:48:24 -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 18DEiX3j003109; Mon, 13 Sep 2021 17:44:33 +0300 Received: by taln60.nuvoton.co.il (Postfix, from userid 10140) id AB7FA63A20; Mon, 13 Sep 2021 17:44:43 +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 v14 5/7] tpm: tpm_tis: verify TPM_STS register is valid after locality request Date: Mon, 13 Sep 2021 17:43:49 +0300 Message-Id: <20210913144351.101167-6-amirmizi6@gmail.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20210913144351.101167-1-amirmizi6@gmail.com> References: <20210913144351.101167-1-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-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 4145758..d527c43 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 (tpm_tis_wait_for_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