From patchwork Tue Aug 22 23:15:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 13361518 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 870F9EE49AE for ; Tue, 22 Aug 2023 23:15:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231643AbjHVXPZ (ORCPT ); Tue, 22 Aug 2023 19:15:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230519AbjHVXPZ (ORCPT ); Tue, 22 Aug 2023 19:15:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3356CE9; Tue, 22 Aug 2023 16:15:23 -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 76673611AF; Tue, 22 Aug 2023 23:15:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60173C433C8; Tue, 22 Aug 2023 23:15:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692746122; bh=nV+IFIjcUjUr5NTuen91t3f//+1v/zufLJTVPhd3Ra4=; h=From:To:Cc:Subject:Date:From; b=k/at1DXhhWgueWlzkp5tYKsA4+wV/WV74HgVexY4xp8Cmli5rPBbHtJHDqgNOv/s3 foOK4vRVHs9vRI0ILIcR4p4FFYJi3pupv5UVAmTMmcqGzDnfnzDJj8eRWzCxO4UmX6 SrylOnSZZ7RiojGrCLVYj8G2Y0SyYjgxr4Boe+E6N7oGE7yEWMU3Wim18KQJCaMJVe E3L2bIOm/M1sn/7cWZya1DgTGizkIS8F1nExGHfj92zIX2ahAFLPMcZ/tsp7Eimq3q otmIGupevfZNlYuJDZIf979hqhO6+tWqLlI/rMzoRgjD94CwWkTL7AfxEOXzgSBCFl 8CWvRBfB87pxQ== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: Jerry Snitselaar , Jarkko Sakkinen , stable@vger.kernel.org, Todd Brandt , Peter Huewe , Jason Gunthorpe , Mario Limonciello , linux-kernel@vger.kernel.org Subject: [PATCH v3] tpm: Enable hwrng only for Pluton on AMD CPUs Date: Wed, 23 Aug 2023 02:15:10 +0300 Message-Id: <20230822231510.2263255-1-jarkko@kernel.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org The vendor check introduced by commit 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs") doesn't work properly on a number of Intel fTPMs. On the reported systems the TPM doesn't reply at bootup and returns back the command code. This makes the TPM fail probe. Since only Microsoft Pluton is the only known combination of AMD CPU and fTPM from other vendor, disable hwrng otherwise. In order to make sysadmin aware of this, print also info message to the klog. Cc: stable@vger.kernel.org Fixes: 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs") Reported-by: Todd Brandt Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217804 Signed-off-by: Jarkko Sakkinen Reported-by: Patrick Steinhardt Reported-by: Ronan Pigott Reported-by: Raymond Jay Golo Reported-by: Patrick Steinhardt Reported-by: Ronan Pigott Reported-by: Ronan Pigott Reported-by: Raymond Jay Golo Reported-by: Raymond Jay Golo Signed-off-by: Jarkko Sakkinen Reviewed-by: Jerry Snitselaar --- v3: * Forgot to amend config flags. v2: * CONFIG_X86 * Removed "Reviewed-by: Jarkko Sakkinen " * Removed "Signed-off-by: Mario Limonciello " --- drivers/char/tpm/tpm_crb.c | 33 ++++++++------------------------- 1 file changed, 8 insertions(+), 25 deletions(-) diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index 65ff4d2fbe8d..ea085b14ab7c 100644 --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -463,28 +463,6 @@ static bool crb_req_canceled(struct tpm_chip *chip, u8 status) 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, @@ -827,9 +805,14 @@ static int crb_acpi_add(struct acpi_device *device) if (rc) goto out; - rc = crb_check_flags(chip); - if (rc) - goto out; +#ifdef CONFIG_X86 + /* A quirk for https://www.amd.com/en/support/kb/faq/pa-410 */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD && + priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) { + dev_info(dev, "Disabling hwrng\n"); + chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED; + } +#endif /* CONFIG_X86 */ rc = tpm_chip_register(chip);