From nobody Fri Nov 29 18:35:56 2024 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 739B4188A37; Tue, 17 Sep 2024 15:45:19 +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=1726587919; cv=none; b=P0cdgy9nd3U4unjln69ubJKj8yBlchNs5rV2an7z3DjpFKWCqiFu62LFwDTzmmvCDHPYcKb1f9/4PA6P4R5deozYIwcXtsU5ZI0txT29J2+a0wgcF/NPg8spUS5kBcKectzriVUbpjJMJ1hGNJcks+fOHPZ2dVP7XXJhyww/MWQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726587919; c=relaxed/simple; bh=ierCK7VWxvo8wK6md4TR1uHJ+m5L2VbdufMWxne1uCA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lGtrpvzGG2sOzQxOOZNS0/yzm/BpaoN1uUG7QNTA3QCUos+8R9zBvAa3kBE7nwtnvOQMjhQiuiixTKHZxuI7Uke7f0b46TFJSltcrZxjOTL7BwS1lrvNkuH+rpNHI6SXBlE5PLVCVrc196kbPyHPPDq/f3+yj5gtRU3Dcmf5OCo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PrJh4aC1; 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="PrJh4aC1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80299C4CEC5; Tue, 17 Sep 2024 15:45:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726587919; bh=ierCK7VWxvo8wK6md4TR1uHJ+m5L2VbdufMWxne1uCA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PrJh4aC16spska4hn1hVdh+hmAbymnIz/1CZozeUYlaPJhL2+N+MrD4vTVvHMLtXh uYjE4X2rMq1stohIGUCCxOr0LzKNKaBcxBNil/cocBKfZIqt3wPhUn30/GC60cXC0L 0LiZg2KMWtsNrxYp3LbI36F+Z4DYXz89V53ioc+P3xm+/+busembyoWql9rIKz66fa 09CKz24YCPivPJ8iLTLnaCxgvXzGRJMdxSd7X39FiYLBt303Jem+aI2/YuLbKcoUld 35QX4/k2A5OK2zXCrxALvYa6oHkaXAdYvK1Gh6RGsW9vtgCWsYyw0viU18u3YzDtcm GqcNQWwcOzWAw== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: James.Bottomley@HansenPartnership.com, roberto.sassu@huawei.com, mapengyu@gmail.com, Jarkko Sakkinen , Mimi Zohar , David Howells , Paul Moore , James Morris , "Serge E. Hallyn" , keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 6/7] tpm: flush the auth session only when /dev/tpm0 is open Date: Tue, 17 Sep 2024 18:44:35 +0300 Message-ID: <20240917154444.702370-7-jarkko@kernel.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240917154444.702370-1-jarkko@kernel.org> References: <20240917154444.702370-1-jarkko@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Instead of flushing and reloading the auth session for every single transaction, keep the session open unless /dev/tpm0 is used. In practice this means applying TPM2_SA_CONTINUE_SESSION to the session attributes. Flush the session always when /dev/tpm0 is written. This reduces the number of TPM2_ContextLoad and TPM2_FlushContext commands Signed-off-by: Jarkko Sakkinen --- v3: - Refined the commit message. - Removed the conditional for applying TPM2_SA_CONTINUE_SESSION only when /dev/tpm0 is open. It is not required as the auth session is flushed, not saved. v2: - A new patch. --- drivers/char/tpm/tpm-chip.c | 1 + drivers/char/tpm/tpm-dev-common.c | 1 + drivers/char/tpm/tpm-interface.c | 1 + drivers/char/tpm/tpm2-sessions.c | 3 +++ 4 files changed, 6 insertions(+) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 0ea00e32f575..7a6bb30d1f32 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -680,6 +680,7 @@ void tpm_chip_unregister(struct tpm_chip *chip) rc =3D tpm_try_get_ops(chip); if (!rc) { if (chip->flags & TPM_CHIP_FLAG_TPM2) { + tpm2_end_auth_session(chip); tpm2_flush_context(chip, chip->null_key); chip->null_key =3D 0; } diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-c= ommon.c index 4bc07963e260..c6fdeb4feaef 100644 --- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c @@ -29,6 +29,7 @@ static ssize_t tpm_dev_transmit(struct tpm_chip *chip, st= ruct tpm_space *space, =20 #ifdef CONFIG_TCG_TPM2_HMAC if (chip->flags & TPM_CHIP_FLAG_TPM2) { + tpm2_end_auth_session(chip); tpm2_flush_context(chip, chip->null_key); chip->null_key =3D 0; } diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interf= ace.c index bfa47d48b0f2..2363018fa8fb 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -381,6 +381,7 @@ int tpm_pm_suspend(struct device *dev) if (!rc) { if (chip->flags & TPM_CHIP_FLAG_TPM2) { #ifdef CONFIG_TCG_TPM2_HMAC + tpm2_end_auth_session(chip); tpm2_flush_context(chip, chip->null_key); chip->null_key =3D 0; #endif diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessi= ons.c index 43b8e3576232..d240039d0849 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -268,6 +268,9 @@ void tpm_buf_append_hmac_session(struct tpm_chip *chip,= struct tpm_buf *buf, } =20 #ifdef CONFIG_TCG_TPM2_HMAC + /* The first write to /dev/tpm{rm0} will flush the session. */ + attributes |=3D TPM2_SA_CONTINUE_SESSION; + /* * The Architecture Guide requires us to strip trailing zeros * before computing the HMAC --=20 2.46.0