From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ED8513148C2; Mon, 13 Oct 2025 15:42:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760370140; cv=none; b=Ak8xQU+dZYH+0tONtscGFR3gA7l4uXAPUkDVc2wXMp9fj/J0jgFFq0APvseXoo0hmPfEF1oOG2Iu2YMJLjI9f/3A7TGCzfkhBTDBX2tV1MMfQVTFMBwHr9CMk1CzdyE5JXpo2OTetosTZuIqZJzFSsM1BkOvxEMNMReccjOhEAs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760370140; c=relaxed/simple; bh=Hom9tn8NgRZspiTioJrxeCD0f/oU2g6MhZSLzOJrjwc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LHljghcPwsbniW+vNpJhSwdUrWm6OlDx/mTbMdbrHaY+PlVDjeDn29hciCx0NhigFfCKDKkBcYWpP2ku00NFrhzk+4zq2DWptgRUfansi9pgOQxYhf9XrSSBO6VuS8hnZ1emF+MeVD1r+NoseyToO6EbiP7LjCDB5kqOSfavUUo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lsP523OI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="lsP523OI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75743C4CEE7; Mon, 13 Oct 2025 15:42:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760370139; bh=Hom9tn8NgRZspiTioJrxeCD0f/oU2g6MhZSLzOJrjwc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lsP523OIWMJUgY6MmOdjQTFZRlxegmLKxomLAWtvCVNvc0nECMRzQpQaySnfjjwb3 US+hMMdEwhj7o2OzCWHP0ECxxbrno2IzROB3WhVpeEZJu1CSYUKaT2gDPflXdYGzdQ mvHZABpIok+BxCVOVm8GahFPNThC8efa9RfSSeqw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chris Fenner , Jarkko Sakkinen , stable@vger.kernel.or Subject: [PATCH 6.17 493/563] tpm: Disable TPM2_TCG_HMAC by default Date: Mon, 13 Oct 2025 16:45:54 +0200 Message-ID: <20251013144429.152278910@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013144411.274874080@linuxfoundation.org> References: <20251013144411.274874080@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jarkko Sakkinen commit 4bddf4587c131d7b8ce8952cd32b284dcda0dd1f upstream. After reading all the feedback, right now disabling the TPM2_TCG_HMAC is the right call. Other views discussed: A. Having a kernel command-line parameter or refining the feature otherwise. This goes to the area of improvements. E.g., one example is my own idea where the null key specific code would be replaced with a persistent handle parameter (which can be *unambigously* defined as part of attestation process when done correctly). B. Removing the code. I don't buy this because that is same as saying that HMAC encryption cannot work at all (if really nitpicking) in any form. Also I disagree on the view that the feature could not be refined to something more reasoable. Also, both A and B are worst options in terms of backporting. Thuss, this is the best possible choice. Cc: stable@vger.kernel.or # v6.10+ Fixes: d2add27cf2b8 ("tpm: Add NULL primary creation") Suggested-by: Chris Fenner Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -29,7 +29,7 @@ if TCG_TPM config TCG_TPM2_HMAC bool "Use HMAC and encrypted transactions on the TPM bus" - default X86_64 + default n select CRYPTO_ECDH select CRYPTO_LIB_AESCFB select CRYPTO_LIB_SHA256