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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C3A1EB64DD for ; Sun, 13 Aug 2023 21:24:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231440AbjHMVYG (ORCPT ); Sun, 13 Aug 2023 17:24:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231421AbjHMVYF (ORCPT ); Sun, 13 Aug 2023 17:24:05 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80CE810EA for ; Sun, 13 Aug 2023 14:24:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1CD5D628B4 for ; Sun, 13 Aug 2023 21:24:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BC80C433C7; Sun, 13 Aug 2023 21:24:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691961845; bh=WBhgL/98sI1Q+PMVwRtyWLFC6/NQXjMe0NjnBnC29Is=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sNQFbg61RFTBiyP9B29UWs4jJzGAJuqKe0VOZRpgCDig5DYvqX2CiRXFSlFhFyhvi 4sV4Pv0C05ercwwQO60jV3H2BiSrSRUCYy2AYlrqh4fQwEiwhkoBmQm7FAvxqkkwJa zK2+/xi95bmAbO6fFbYUdhlPO7XoK3sBOtgvBo7E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, daniil.stas@posteo.net, bitlord0xff@gmail.com, Mario Limonciello , Jarkko Sakkinen Subject: [PATCH 6.4 002/206] tpm: Disable RNG for all AMD fTPMs Date: Sun, 13 Aug 2023 23:16:12 +0200 Message-ID: <20230813211725.045201856@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230813211724.969019629@linuxfoundation.org> References: <20230813211724.969019629@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mario Limonciello commit 554b841d470338a3b1d6335b14ee1cd0c8f5d754 upstream. The TPM RNG functionality is not necessary for entropy when the CPU already supports the RDRAND instruction. The TPM RNG functionality was previously disabled on a subset of AMD fTPM series, but reports continue to show problems on some systems causing stutter root caused to TPM RNG functionality. Expand disabling TPM RNG use for all AMD fTPMs whether they have versions that claim to have fixed or not. To accomplish this, move the detection into part of the TPM CRB registration and add a flag indicating that the TPM should opt-out of registration to hwrng. Cc: stable@vger.kernel.org # 6.1.y+ Fixes: b006c439d58d ("hwrng: core - start hwrng kthread also for untrusted sources") Fixes: f1324bbc4011 ("tpm: disable hwrng for fTPM on some AMD designs") Reported-by: daniil.stas@posteo.net Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217719 Reported-by: bitlord0xff@gmail.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217212 Signed-off-by: Mario Limonciello Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm-chip.c | 68 +------------------------------------------- drivers/char/tpm/tpm_crb.c | 30 +++++++++++++++++++ include/linux/tpm.h | 1 3 files changed, 33 insertions(+), 66 deletions(-) --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -510,70 +510,6 @@ static int tpm_add_legacy_sysfs(struct t return 0; } -/* - * Some AMD fTPM versions may cause stutter - * https://www.amd.com/en/support/kb/faq/pa-410 - * - * Fixes are available in two series of fTPM firmware: - * 6.x.y.z series: 6.0.18.6 + - * 3.x.y.z series: 3.57.y.5 + - */ -#ifdef CONFIG_X86 -static bool tpm_amd_is_rng_defective(struct tpm_chip *chip) -{ - u32 val1, val2; - u64 version; - int ret; - - if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) - return false; - - ret = tpm_request_locality(chip); - if (ret) - return false; - - ret = tpm2_get_tpm_pt(chip, TPM2_PT_MANUFACTURER, &val1, NULL); - if (ret) - goto release; - if (val1 != 0x414D4400U /* AMD */) { - ret = -ENODEV; - goto release; - } - ret = tpm2_get_tpm_pt(chip, TPM2_PT_FIRMWARE_VERSION_1, &val1, NULL); - if (ret) - goto release; - ret = tpm2_get_tpm_pt(chip, TPM2_PT_FIRMWARE_VERSION_2, &val2, NULL); - -release: - tpm_relinquish_locality(chip); - - if (ret) - return false; - - version = ((u64)val1 << 32) | val2; - if ((version >> 48) == 6) { - if (version >= 0x0006000000180006ULL) - return false; - } else if ((version >> 48) == 3) { - if (version >= 0x0003005700000005ULL) - return false; - } else { - return false; - } - - dev_warn(&chip->dev, - "AMD fTPM version 0x%llx causes system stutter; hwrng disabled\n", - version); - - return true; -} -#else -static inline bool tpm_amd_is_rng_defective(struct tpm_chip *chip) -{ - return false; -} -#endif /* CONFIG_X86 */ - static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait) { struct tpm_chip *chip = container_of(rng, struct tpm_chip, hwrng); @@ -588,7 +524,7 @@ static int tpm_hwrng_read(struct hwrng * static int tpm_add_hwrng(struct tpm_chip *chip) { if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM) || tpm_is_firmware_upgrade(chip) || - tpm_amd_is_rng_defective(chip)) + chip->flags & TPM_CHIP_FLAG_HWRNG_DISABLED) return 0; snprintf(chip->hwrng_name, sizeof(chip->hwrng_name), @@ -719,7 +655,7 @@ void tpm_chip_unregister(struct tpm_chip { tpm_del_legacy_sysfs(chip); if (IS_ENABLED(CONFIG_HW_RANDOM_TPM) && !tpm_is_firmware_upgrade(chip) && - !tpm_amd_is_rng_defective(chip)) + !(chip->flags & TPM_CHIP_FLAG_HWRNG_DISABLED)) hwrng_unregister(&chip->hwrng); tpm_bios_log_teardown(chip); if (chip->flags & TPM_CHIP_FLAG_TPM2 && !tpm_is_firmware_upgrade(chip)) --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -463,6 +463,28 @@ static bool crb_req_canceled(struct tpm_ return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE; } +static int crb_check_flags(struct tpm_chip *chip) +{ + u32 val; + int ret; + + ret = crb_request_locality(chip, 0); + if (ret) + return ret; + + ret = tpm2_get_tpm_pt(chip, TPM2_PT_MANUFACTURER, &val, NULL); + if (ret) + goto release; + + if (val == 0x414D4400U /* AMD */) + chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED; + +release: + crb_relinquish_locality(chip, 0); + + return ret; +} + static const struct tpm_class_ops tpm_crb = { .flags = TPM_OPS_AUTO_STARTUP, .status = crb_status, @@ -800,6 +822,14 @@ static int crb_acpi_add(struct acpi_devi chip->acpi_dev_handle = device->handle; chip->flags = TPM_CHIP_FLAG_TPM2; + rc = tpm_chip_bootstrap(chip); + if (rc) + goto out; + + rc = crb_check_flags(chip); + if (rc) + goto out; + rc = tpm_chip_register(chip); out: --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -283,6 +283,7 @@ enum tpm_chip_flags { TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED = BIT(6), TPM_CHIP_FLAG_FIRMWARE_UPGRADE = BIT(7), TPM_CHIP_FLAG_SUSPENDED = BIT(8), + TPM_CHIP_FLAG_HWRNG_DISABLED = BIT(9), }; #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)