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 517EF26529E; Thu, 31 Jul 2025 21:24:07 +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=1753997048; cv=none; b=i+ZhOtcIqPEEy4ayFb4vxC77i9GHITNV/f7XDBBUYvk5psow4bwzYsrcqmRgj4mi1WaIekxn8I8k+B/gTjqRTMV1FJveqPbNF6Mp86izdRjJ1PBpB/9SSHxYyRI9UJYq0YCEEcGH0l7zSE5bf7+MKCB86lWXEmE3weiM++LbiqM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753997048; c=relaxed/simple; bh=10xZrZKLy96+1t62WkYqn4As03OohTGiwGgJNIB8B4M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tpi2Etus8SPb9jAYcAmk+6NfTV5JYdgKHUyJZK8b8kL+uRkY/IPeuvMSosS48WdxAkoNKLdFMSAv9b0+WE777/eF/57Jvhq5/k9pQ7Sr3/fHMRWoHrE+sLJe+qIPMQDkUShNf2LHhPXTlISMwCYxh5fRlgUNkmzxhwRXa2X81Nw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=k8Hb6FUM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="k8Hb6FUM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 72022C4CEF4; Thu, 31 Jul 2025 21:24:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753997047; bh=10xZrZKLy96+1t62WkYqn4As03OohTGiwGgJNIB8B4M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k8Hb6FUMjgP21mHoTL9VejxjZU0DhmEzyG7xb5xkrOzrpPJoJFhQkVAcV/pUQtBgE AU7VIRfGRvymEPjZxNAB1cv4g/Bw1NMuvdLQ9yp/vLS+soFkgE7DsZ5JNO/uTfV0Yy vP80KVJvGB6E6gkk31AElo1emKRo56Y5+aPxLLzAOgG8uo+xTFaQsuWrTqyTQi9XE4 Q/y3PrcdZPvvTTAohvY3uJPMpOhdInb3UQfc4X5unCcpPTD6vJ95xow6aRJGt0/PY5 iFTNvhBE5sJvHydLEWKK9ESeeiTEx3KMZMYBoFgbkxCLn/YMvPXHYQjcG5vdHERODq Yo6DD5f+TQOgQ== From: Eric Biggers To: James Bottomley , Jarkko Sakkinen , Mimi Zohar , keyrings@vger.kernel.org Cc: David Howells , linux-integrity@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Eric Biggers , stable@vger.kernel.org Subject: [PATCH 1/3] KEYS: trusted_tpm1: Compare HMAC values in constant time Date: Thu, 31 Jul 2025 14:23:52 -0700 Message-ID: <20250731212354.105044-2-ebiggers@kernel.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250731212354.105044-1-ebiggers@kernel.org> References: <20250731212354.105044-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To prevent timing attacks, HMAC value comparison needs to be constant time. Replace the memcmp() with the correct function, crypto_memneq(). Fixes: d00a1c72f7f4 ("keys: add new trusted key-type") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers --- security/keys/trusted-keys/trusted_tpm1.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index 89c9798d18007..e73f2c6c817a0 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -5,10 +5,11 @@ * * See Documentation/security/keys/trusted-encrypted.rst */ #include +#include #include #include #include #include #include @@ -239,11 +240,11 @@ int TSS_checkhmac1(unsigned char *buffer, TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce, 1, continueflag, 0, 0); if (ret < 0) goto out; - if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE)) + if (crypto_memneq(testhmac, authdata, SHA1_DIGEST_SIZE)) ret = -EINVAL; out: kfree_sensitive(sdesc); return ret; } @@ -332,20 +333,20 @@ static int TSS_checkhmac2(unsigned char *buffer, ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE, paramdigest, TPM_NONCE_SIZE, enonce1, TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0); if (ret < 0) goto out; - if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) { + if (crypto_memneq(testhmac1, authdata1, SHA1_DIGEST_SIZE)) { ret = -EINVAL; goto out; } ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE, paramdigest, TPM_NONCE_SIZE, enonce2, TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0); if (ret < 0) goto out; - if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE)) + if (crypto_memneq(testhmac2, authdata2, SHA1_DIGEST_SIZE)) ret = -EINVAL; out: kfree_sensitive(sdesc); return ret; } base-commit: d6084bb815c453de27af8071a23163a711586a6c -- 2.50.1