From nobody Tue Nov 26 08:40:06 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 C8FB41CEEAF; Mon, 21 Oct 2024 05:39:45 +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=1729489186; cv=none; b=e4FHZQ7nveDlE6/MpPAYK3Ah8Fw06/ziFWpYfHjWumlhUtSq6bo2jVM73CahOMqi1t6Pgvoh1Yxjdt2t5gecgG03aMfiVdKbdPhv1YM4IP8V+f5BFPwBtm7hDgU6vBaD7DuAwmZ4GxDXDWE/ki6f5iKPvMACXR67QoHd8xCKqhc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729489186; c=relaxed/simple; bh=sBQVOg/eM0xgxq2VxksERP5qeqkNKWn0D8iRZXy3xho=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=t2ofjmreodnKvvo4g1WbkHg3N56w8GyqpE6qoMZk7sPxlHf6NHBOdsC3b1XwNnWsHyTP/fWGoRoBjadSabgDZoxA6iQQ/SNkXc9WjzREkxEq8gxyUEyjGUsA81gLHUaCq0+whb5S1J+KOkk1YYwZy44XSLPCD/vCc6Ys0nZyIDE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VcpXxa1L; 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="VcpXxa1L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D72C0C4CEC3; Mon, 21 Oct 2024 05:39:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729489185; bh=sBQVOg/eM0xgxq2VxksERP5qeqkNKWn0D8iRZXy3xho=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VcpXxa1LXY6VcB6yfZJuUu1qwJqPY/5TBR9c4Jnv5JtlrMCPHz67D5oZ0LZ+1JOwJ dqZUfPTlQxsoP1wy8TBym5VNUK3v55zIahZVuLTqwSM/Gu3kO4axQ0a+tkhi1Rs6Zy Bmh53Wv8o8wZkP4Zr3FqnbR57w6qZJ+I0EyMNMlgwbagHDFiWOZU/QRVPdQn4UlhnY HV9tvN6dBGyzVCCl7GL9OqiYdp+wAEHSCyNAU9wWFkPjddlCNAHmRI9UjrhAY9Lk4f fnm5B3jUvcJozSwZ+w5UvgTPwYbaRDLiE8P4NBlqkqelF/Dc5zOCqDbX7W14K5c7Cj wC+SP8Ar2J69g== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org, Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , James Bottomley Cc: David Howells , Mimi Zohar , Roberto Sassu , Stefan Berger , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Pengyu Ma Subject: [PATCH v7 3/5] tpm: flush the null key only when /dev/tpm0 is accessed Date: Mon, 21 Oct 2024 08:39:17 +0300 Message-ID: <20241021053921.33274-4-jarkko@kernel.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241021053921.33274-1-jarkko@kernel.org> References: <20241021053921.33274-1-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 null key for every single auth session, flush it only when: 1. User space needs to access /dev/tpm{rm}0. 2. When going to sleep. 3. When unregistering the chip. This removes the need to load and swap the null key between TPM and regular memory per transaction, when the user space is not using the chip. Cc: stable@vger.kernel.org # v6.10+ Fixes: d2add27cf2b8 ("tpm: Add NULL primary creation") Tested-by: Pengyu Ma Signed-off-by: Jarkko Sakkinen --- v5: - No changes. v4: - Changed to bug fix as not having the patch there is a major hit to bootup times. v3: - Unchanged. v2: - Refined the commit message. - Added tested-by from Pengyu Ma . - Removed spurious pr_info() statement. --- drivers/char/tpm/tpm-chip.c | 13 +++++++++++++ drivers/char/tpm/tpm-dev-common.c | 7 +++++++ drivers/char/tpm/tpm-interface.c | 9 +++++++-- drivers/char/tpm/tpm2-cmd.c | 3 +++ drivers/char/tpm/tpm2-sessions.c | 17 ++++++++++++++--- include/linux/tpm.h | 2 ++ 6 files changed, 46 insertions(+), 5 deletions(-) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 854546000c92..0ea00e32f575 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -674,6 +674,19 @@ EXPORT_SYMBOL_GPL(tpm_chip_register); */ void tpm_chip_unregister(struct tpm_chip *chip) { +#ifdef CONFIG_TCG_TPM2_HMAC + int rc; + + rc =3D tpm_try_get_ops(chip); + if (!rc) { + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + tpm2_flush_context(chip, chip->null_key); + chip->null_key =3D 0; + } + tpm_put_ops(chip); + } +#endif + tpm_del_legacy_sysfs(chip); if (tpm_is_hwrng_enabled(chip)) hwrng_unregister(&chip->hwrng); diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-c= ommon.c index 30b4c288c1bb..4eaa8e05c291 100644 --- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c @@ -27,6 +27,13 @@ static ssize_t tpm_dev_transmit(struct tpm_chip *chip, s= truct tpm_space *space, struct tpm_header *header =3D (void *)buf; ssize_t ret, len; =20 +#ifdef CONFIG_TCG_TPM2_HMAC + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + tpm2_flush_context(chip, chip->null_key); + chip->null_key =3D 0; + } +#endif + ret =3D tpm2_prepare_space(chip, space, buf, bufsiz); /* If the command is not implemented by the TPM, synthesize a * response with a TPM2_RC_COMMAND_CODE return for user-space. diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interf= ace.c index 5da134f12c9a..bfa47d48b0f2 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -379,10 +379,15 @@ int tpm_pm_suspend(struct device *dev) =20 rc =3D tpm_try_get_ops(chip); if (!rc) { - if (chip->flags & TPM_CHIP_FLAG_TPM2) + if (chip->flags & TPM_CHIP_FLAG_TPM2) { +#ifdef CONFIG_TCG_TPM2_HMAC + tpm2_flush_context(chip, chip->null_key); + chip->null_key =3D 0; +#endif tpm2_shutdown(chip, TPM2_SU_STATE); - else + } else { rc =3D tpm1_pm_suspend(chip, tpm_suspend_pcr); + } =20 tpm_put_ops(chip); } diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 1e856259219e..aba024cbe7c5 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -364,6 +364,9 @@ void tpm2_flush_context(struct tpm_chip *chip, u32 hand= le) struct tpm_buf buf; int rc; =20 + if (!handle) + return; + rc =3D tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT); if (rc) { dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n", diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessi= ons.c index bdac11964b55..78c650ce4c9f 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -920,11 +920,19 @@ static int tpm2_load_null(struct tpm_chip *chip, u32 = *null_key) u32 tmp_null_key; int rc; =20 + /* fast path */ + if (chip->null_key) { + *null_key =3D chip->null_key; + return 0; + } + rc =3D tpm2_load_context(chip, chip->null_key_context, &offset, &tmp_null_key); if (rc !=3D -EINVAL) { - if (!rc) + if (!rc) { + chip->null_key =3D tmp_null_key; *null_key =3D tmp_null_key; + } goto err; } =20 @@ -934,6 +942,7 @@ static int tpm2_load_null(struct tpm_chip *chip, u32 *n= ull_key) =20 /* Return the null key if the name has not been changed: */ if (memcmp(name, chip->null_key_name, sizeof(name)) =3D=3D 0) { + chip->null_key =3D tmp_null_key; *null_key =3D tmp_null_key; return 0; } @@ -1006,7 +1015,6 @@ int tpm2_start_auth_session(struct tpm_chip *chip) tpm_buf_append_u16(&buf, TPM_ALG_SHA256); =20 rc =3D tpm_transmit_cmd(chip, &buf, 0, "start auth session"); - tpm2_flush_context(chip, null_key); =20 if (rc =3D=3D TPM2_RC_SUCCESS) rc =3D tpm2_parse_start_auth_session(auth, &buf); @@ -1338,7 +1346,10 @@ static int tpm2_create_null_primary(struct tpm_chip = *chip) =20 rc =3D tpm2_save_context(chip, null_key, chip->null_key_context, sizeof(chip->null_key_context), &offset); - tpm2_flush_context(chip, null_key); + if (rc) + tpm2_flush_context(chip, null_key); + else + chip->null_key =3D null_key; } =20 return rc; diff --git a/include/linux/tpm.h b/include/linux/tpm.h index e93ee8d936a9..4eb39db80e05 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -205,6 +205,8 @@ struct tpm_chip { #ifdef CONFIG_TCG_TPM2_HMAC /* details for communication security via sessions */ =20 + /* loaded null key */ + u32 null_key; /* saved context for NULL seed */ u8 null_key_context[TPM2_MAX_CONTEXT_SIZE]; /* name of NULL seed */ --=20 2.47.0