From nobody Mon Nov 25 11:37:18 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 6AE9018DF7B; Mon, 28 Oct 2024 05:50:25 +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=1730094625; cv=none; b=krz1O0ZCjvwE/YxAcF0wWCkpi6HbdU3YH2lnVQe4XuMQ7mq6hQag1eZEEUGhrhUypLDBMKOGVOkJmTCMOk3ZdxYlAH/O4QWTdMr6XVqyB8Fntm7ISyZYwenTNfxCLYRRK5EFR16yqRuNGoI7Yha/TzHQ9SRw1cITtqw9g6wZyKI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730094625; c=relaxed/simple; bh=cphvGT84GpWQdpKAIyfVpKkY71YTs0aVCk6EV1mh/Lc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GadcqZI0wR0HKqxO6SJXFvg/GSSfsQUpmXyKnKW/9mL4SiNANUIYT2aUey3VeftxEyzQ4ARIntfzZfjaH/2YvJ5TMhMI/V+lAABzhFVF6aRHO3K+tCoVCWAM4Tem+SAyMXgRfGRXTY7dG7437LdhN3ELV3lY4vdODS0pLIUtPd4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uTtuA7QU; 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="uTtuA7QU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CAA0C4CEC3; Mon, 28 Oct 2024 05:50:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730094625; bh=cphvGT84GpWQdpKAIyfVpKkY71YTs0aVCk6EV1mh/Lc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uTtuA7QUYZswPSu3j8yKgx7hvjTM4TiKnXDnkS5abTEXhfg6EmiRiLMwTGk77o8Qr P3fq7fyGoo75+YX8A/HAys7Zsu/LQKImvwgUgvZBIdJXmAFwIczBCWovDIQ0qXHmTT 1nR7dEVXUDNXx0BEsN9G0nqJxMbrrMjrJCiIn//BQ9schZbzYf7s3Ixky829+nv+hY fwpXJ7RK8VLdGcN3+Fe1GYzS1kZpCtagRd8dZstgefSFNYCciyvYX2i3MF5aSEZfdU ELC/kXjPDS/e35O0vPJgOwcr2tbu3NrUbCxDMHUTe3+EZwqH4puT0TgCyfldTcfeHf e0Z6djDubZKOQ== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org, Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , James Bottomley Cc: linux-kernel@vger.kernel.org, David Howells , Mimi Zohar , Roberto Sassu , Stefan Berger , Paul Moore , James Morris , "Serge E. Hallyn" , Dmitry Kasatkin , Eric Snowberg , keyrings@vger.kernel.org (open list:KEYS-TRUSTED), linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM), stable@vger.kernel.org Subject: [PATCH v8 1/3] tpm: Return tpm2_sessions_init() when null key creation fails Date: Mon, 28 Oct 2024 07:49:59 +0200 Message-ID: <20241028055007.1708971-2-jarkko@kernel.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241028055007.1708971-1-jarkko@kernel.org> References: <20241028055007.1708971-1-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" Do not continue tpm2_sessions_init() further if the null key pair creation fails. Cc: stable@vger.kernel.org # v6.10+ Fixes: d2add27cf2b8 ("tpm: Add NULL primary creation") Signed-off-by: Jarkko Sakkinen Reviewed-by: Stefan Berger --- v8: - Refine commit message. v7: - Add the error message back but fix it up a bit: 1. Remove 'TPM:' given dev_err(). 2. s/NULL/null/ as this has nothing to do with the macro in libc. 3. Fix the reasoning: null key creation failed v6: - Address: https://lore.kernel.org/linux-integrity/69c893e7-6b87-4daa-80db-44d1120e8= 0fe@linux.ibm.com/ as TPM RC is taken care of at the call site. Add also the missing documentation for the return values. v5: - Do not print klog messages on error, as tpm2_save_context() already takes care of this. v4: - Fixed up stable version. v3: - Handle TPM and POSIX error separately and return -ENODEV always back to the caller. v2: - Refined the commit message. --- drivers/char/tpm/tpm2-sessions.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessi= ons.c index d3521aadd43e..a0306126e86c 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -1347,14 +1347,21 @@ static int tpm2_create_null_primary(struct tpm_chip= *chip) * * Derive and context save the null primary and allocate memory in the * struct tpm_chip for the authorizations. + * + * Return: + * * 0 - OK + * * -errno - A system error + * * TPM_RC - A TPM error */ int tpm2_sessions_init(struct tpm_chip *chip) { int rc; =20 rc =3D tpm2_create_null_primary(chip); - if (rc) - dev_err(&chip->dev, "TPM: security failed (NULL seed derivation): %d\n",= rc); + if (rc) { + dev_err(&chip->dev, "null key creation failed with %d\n", rc); + return rc; + } =20 chip->auth =3D kmalloc(sizeof(*chip->auth), GFP_KERNEL); if (!chip->auth) --=20 2.47.0 From nobody Mon Nov 25 11:37:18 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 CA2FF18CBF9; Mon, 28 Oct 2024 05:50:30 +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=1730094630; cv=none; b=prFOJtVvNe+Bns9D4Sd0+xxZ5Z47lcFIayzcAVw8L91r6yn24zhi6P3/rqyAlvGX3GR40+S+ITgZPy/v2fWJTP0R6nQ/nB2UXwfT7ziZxef71riLr7rWqGGKZYGWbdpM0mh9MIxcqamD7GRE4n1FPQyFGnB8lW/yX9VfOp2kWvc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730094630; c=relaxed/simple; bh=XCl1yMmjSZe/N+58hVzZinUX+FhB2RuhENSeqHEfICA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ru1oP15EwOtYBUPFYhYdUqmY7nyL94pXpefTu0Sk9UtZrztcP18VIxtAMfZM+BmrCSIrJ//aNSSxVbw/dyWmXAckCUjxaygmtSZfmbzfsxlUVyGHwYJtnalK+nKthpQo27no4aa1ABlLHb8SQATFq93opPvE1Plij2dbyZbcujA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ClqiLAlM; 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="ClqiLAlM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35271C4CEC3; Mon, 28 Oct 2024 05:50:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730094630; bh=XCl1yMmjSZe/N+58hVzZinUX+FhB2RuhENSeqHEfICA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ClqiLAlMkiN/DrZw9ugwPsZjE2a13LnBH68M15USUJdgIri7wqh6mvs/pgttHRWSi fh6X75u8MZzEDqsgwQNfWGkXs9XSBIB9HGl6vtEP4jTgRoTSUSB9eR7fTlUSXyw9fx a6JdOd9vNNUaYKnS/x1YWqoXmYpBnQebIuWPGivtyarv+vWoBczqRw0k+Dwt/mBKlD 99fhbfzxyz38qwsSEPftm6L/4vzKNxNLcaUR/zd1pELSVueMBlXiMpF61Xx+YYr/eI IoGU2yk7t2EQhKjOhjVXRVqhMMYgFKtgvuVAyXXc7sU+Ge9573Xh1WlsI06YJv1upn JQrbqkF5YGf7Q== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org, Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , James Bottomley Cc: linux-kernel@vger.kernel.org, David Howells , Mimi Zohar , Roberto Sassu , Stefan Berger , Paul Moore , James Morris , "Serge E. Hallyn" , Dmitry Kasatkin , Eric Snowberg , keyrings@vger.kernel.org (open list:KEYS-TRUSTED), linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM), stable@vger.kernel.org Subject: [PATCH v8 2/3] tpm: Rollback tpm2_load_null() Date: Mon, 28 Oct 2024 07:50:00 +0200 Message-ID: <20241028055007.1708971-3-jarkko@kernel.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241028055007.1708971-1-jarkko@kernel.org> References: <20241028055007.1708971-1-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" Do not continue on tpm2_create_primary() failure in tpm2_load_null(). Cc: stable@vger.kernel.org # v6.10+ Fixes: eb24c9788cd9 ("tpm: disable the TPM if NULL name changes") Reviewed-by: Stefan Berger Signed-off-by: Jarkko Sakkinen --- v8: - Fix stray character in a log message. v7: - No changes. v6: - Address Stefan's remark: https://lore.kernel.org/linux-integrity/def4ec2d-584b-405f-9d5e-99267013c= 3c0@linux.ibm.com/ v5: - Fix the TPM error code leak from tpm2_load_context(). v4: - No changes. v3: - Update log messages. Previously the log message incorrectly stated on load failure that integrity check had been failed, even tho the check is done *after* the load operation. v2: - Refined the commit message. - Reverted tpm2_create_primary() changes. They are not required if tmp_null_key is used as the parameter. --- drivers/char/tpm/tpm2-sessions.c | 44 +++++++++++++++++--------------- 1 file changed, 24 insertions(+), 20 deletions(-) diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessi= ons.c index a0306126e86c..950a3e48293b 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -915,33 +915,37 @@ static int tpm2_parse_start_auth_session(struct tpm2_= auth *auth, =20 static int tpm2_load_null(struct tpm_chip *chip, u32 *null_key) { - int rc; unsigned int offset =3D 0; /* dummy offset for null seed context */ u8 name[SHA256_DIGEST_SIZE + 2]; + u32 tmp_null_key; + int rc; =20 rc =3D tpm2_load_context(chip, chip->null_key_context, &offset, - null_key); - if (rc !=3D -EINVAL) - return rc; + &tmp_null_key); + if (rc !=3D -EINVAL) { + if (!rc) + *null_key =3D tmp_null_key; + goto err; + } =20 - /* an integrity failure may mean the TPM has been reset */ - dev_err(&chip->dev, "NULL key integrity failure!\n"); - /* check the null name against what we know */ - tpm2_create_primary(chip, TPM2_RH_NULL, NULL, name); - if (memcmp(name, chip->null_key_name, sizeof(name)) =3D=3D 0) - /* name unchanged, assume transient integrity failure */ - return rc; - /* - * Fatal TPM failure: the NULL seed has actually changed, so - * the TPM must have been illegally reset. All in-kernel TPM - * operations will fail because the NULL primary can't be - * loaded to salt the sessions, but disable the TPM anyway so - * userspace programmes can't be compromised by it. - */ - dev_err(&chip->dev, "NULL name has changed, disabling TPM due to interfer= ence\n"); + /* Try to re-create null key, given the integrity failure: */ + rc =3D tpm2_create_primary(chip, TPM2_RH_NULL, &tmp_null_key, name); + if (rc) + goto err; + + /* Return null key if the name has not been changed: */ + if (!memcmp(name, chip->null_key_name, sizeof(name))) { + *null_key =3D tmp_null_key; + return 0; + } + + /* Deduce from the name change TPM interference: */ + dev_err(&chip->dev, "null key integrity check failed\n"); + tpm2_flush_context(chip, tmp_null_key); chip->flags |=3D TPM_CHIP_FLAG_DISABLE; =20 - return rc; +err: + return rc ? -ENODEV : 0; } =20 /** --=20 2.47.0 From nobody Mon Nov 25 11:37:18 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 F260E18D643; Mon, 28 Oct 2024 05:50:36 +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=1730094637; cv=none; b=ETo5za/exDLRg2RPNYIDZsJf/DDNxHfWpAEDJvK97kZ0Q+aaUqJu5hqAcRQ7I5Je1mK1m6yWwmqnI9s/THCEtrFIkffQZsI2fVpPakSnyICFQwDaZJWNLnlrM8/M4Etml21A4jgRRslwH+mqEF6xi+vNJnZcFsaNSsmuMGXM6Xg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730094637; c=relaxed/simple; bh=fRewTVB7pv+APGXOeNKhX+6/qgzbhVlGGPP5SuLFXA8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QeyIigRkMj9vrHt9PPAppHqQz3tnGrl+qRO1KUD6Wt1+zKmW++yFJrXtA96Y4fgseCW91x9J2Yi/xmwFogu0CV0TsmlWCrGb1WIHe8gnoepqCjB2DMBbLUT1VfE3TZT8Eei1fC+ccPIfaQZjRRma2kRBliYE5IRkyqeMHGwLvh8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UoPDTCaA; 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="UoPDTCaA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26600C4CEC3; Mon, 28 Oct 2024 05:50:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730094636; bh=fRewTVB7pv+APGXOeNKhX+6/qgzbhVlGGPP5SuLFXA8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UoPDTCaAapuARW1mojaR4w0c7iAnZj+/m7Dnjw60oVkv1tZXbgT99P1MJk3XJlf+j g9X9W63F6xpkfgKVphutzepxQZMCApZjTicWPCZvz6SsAbQQGyJZCceMwgA5ZI7+8k g8n+u54x+lL5K0/WkCdNcXs1fl5A38Mzqe6gXuMkSjBTcDIRNe6FLgry/7l1Yh2xEG jo1F6n/Es31hyyEKPWn1QMU9FHICtmSg+QT+rmNAEkZjHFXR2xzmQGWZJpyto+hIoI 9Cs4CgnxleRdPO9935qNNKMiBM8Td+qAYlmGLGwWfdsO+z+pfM5Ipwx5s0Dth56r8m swtPv1v4Iyrsg== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org, Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe Cc: linux-kernel@vger.kernel.org, David Howells , James Bottomley , Mimi Zohar , Roberto Sassu , Stefan Berger , Paul Moore , James Morris , "Serge E. Hallyn" , Dmitry Kasatkin , Eric Snowberg , keyrings@vger.kernel.org (open list:KEYS-TRUSTED), linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM), Pengyu Ma , stable@vger.kernel.org Subject: [PATCH v8 3/3] tpm: Lazily flush the auth session Date: Mon, 28 Oct 2024 07:50:01 +0200 Message-ID: <20241028055007.1708971-4-jarkko@kernel.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241028055007.1708971-1-jarkko@kernel.org> References: <20241028055007.1708971-1-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" Move the allocation of chip->auth to tpm2_start_auth_session() so that this field can be used as flag to tell whether auth session is active or not. Instead of flushing and reloading the auth session for every transaction separately, keep the session open unless /dev/tpm0 is used. Reported-by: Pengyu Ma Closes: https://bugzilla.kernel.org/show_bug.cgi?id=3D219229 Cc: stable@vger.kernel.org # v6.10+ Fixes: 7ca110f2679b ("tpm: Address !chip->auth in tpm_buf_append_hmac_sessi= on*()") Tested-by: Pengyu Ma Signed-off-by: Jarkko Sakkinen Reviewed-by: Stefan Berger Tested-by: Stefan Berger --- v8: - Since auth session and null key are flushed at a same time, only either needs to be checked. Addresses and a remark from James Bottomley few revisions ago. - kfree_sensitive() - Effectively squash top three patches given the simplifications. v7: - No changes. v6: - No changes. v5: - No changes. v4: - Changed as bug. 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 | 10 +++++++ drivers/char/tpm/tpm-dev-common.c | 3 +++ drivers/char/tpm/tpm-interface.c | 6 +++-- drivers/char/tpm/tpm2-sessions.c | 45 ++++++++++++++++++------------- 4 files changed, 44 insertions(+), 20 deletions(-) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 854546000c92..1ff99a7091bb 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -674,6 +674,16 @@ 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) { + tpm2_end_auth_session(chip); + 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..c7a88fa7b0fc 100644 --- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c @@ -27,6 +27,9 @@ static ssize_t tpm_dev_transmit(struct tpm_chip *chip, st= ruct tpm_space *space, struct tpm_header *header =3D (void *)buf; ssize_t ret, len; =20 + if (chip->flags & TPM_CHIP_FLAG_TPM2) + tpm2_end_auth_session(chip); + 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..8134f002b121 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -379,10 +379,12 @@ 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) { + tpm2_end_auth_session(chip); 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-sessions.c b/drivers/char/tpm/tpm2-sessi= ons.c index 950a3e48293b..03145a465b5d 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -333,6 +333,9 @@ 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 @@ -484,7 +487,8 @@ static void tpm2_KDFe(u8 z[EC_PT_SZ], const char *str, = u8 *pt_u, u8 *pt_v, sha256_final(&sctx, out); } =20 -static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip) +static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip, + struct tpm2_auth *auth) { struct crypto_kpp *kpp; struct kpp_request *req; @@ -543,7 +547,7 @@ static void tpm_buf_append_salt(struct tpm_buf *buf, st= ruct tpm_chip *chip) sg_set_buf(&s[0], chip->null_ec_key_x, EC_PT_SZ); sg_set_buf(&s[1], chip->null_ec_key_y, EC_PT_SZ); kpp_request_set_input(req, s, EC_PT_SZ*2); - sg_init_one(d, chip->auth->salt, EC_PT_SZ); + sg_init_one(d, auth->salt, EC_PT_SZ); kpp_request_set_output(req, d, EC_PT_SZ); crypto_kpp_compute_shared_secret(req); kpp_request_free(req); @@ -554,8 +558,7 @@ static void tpm_buf_append_salt(struct tpm_buf *buf, st= ruct tpm_chip *chip) * This works because KDFe fully consumes the secret before it * writes the salt */ - tpm2_KDFe(chip->auth->salt, "SECRET", x, chip->null_ec_key_x, - chip->auth->salt); + tpm2_KDFe(auth->salt, "SECRET", x, chip->null_ec_key_x, auth->salt); =20 out: crypto_free_kpp(kpp); @@ -853,7 +856,9 @@ int tpm_buf_check_hmac_response(struct tpm_chip *chip, = struct tpm_buf *buf, if (rc) /* manually close the session if it wasn't consumed */ tpm2_flush_context(chip, auth->handle); - memzero_explicit(auth, sizeof(*auth)); + + kfree_sensitive(auth); + chip->auth =3D NULL; } else { /* reset for next use */ auth->session =3D TPM_HEADER_SIZE; @@ -881,7 +886,8 @@ void tpm2_end_auth_session(struct tpm_chip *chip) return; =20 tpm2_flush_context(chip, auth->handle); - memzero_explicit(auth, sizeof(*auth)); + kfree_sensitive(auth); + chip->auth =3D NULL; } EXPORT_SYMBOL(tpm2_end_auth_session); =20 @@ -962,16 +968,20 @@ static int tpm2_load_null(struct tpm_chip *chip, u32 = *null_key) */ int tpm2_start_auth_session(struct tpm_chip *chip) { + struct tpm2_auth *auth; struct tpm_buf buf; - struct tpm2_auth *auth =3D chip->auth; - int rc; u32 null_key; + int rc; =20 - if (!auth) { - dev_warn_once(&chip->dev, "auth session is not active\n"); + if (chip->auth) { + dev_warn_once(&chip->dev, "auth session is active\n"); return 0; } =20 + auth =3D kzalloc(sizeof(*auth), GFP_KERNEL); + if (!auth) + return -ENOMEM; + rc =3D tpm2_load_null(chip, &null_key); if (rc) goto out; @@ -992,7 +1002,7 @@ int tpm2_start_auth_session(struct tpm_chip *chip) tpm_buf_append(&buf, auth->our_nonce, sizeof(auth->our_nonce)); =20 /* append encrypted salt and squirrel away unencrypted in auth */ - tpm_buf_append_salt(&buf, chip); + tpm_buf_append_salt(&buf, chip, auth); /* session type (HMAC, audit or policy) */ tpm_buf_append_u8(&buf, TPM2_SE_HMAC); =20 @@ -1014,10 +1024,13 @@ int tpm2_start_auth_session(struct tpm_chip *chip) =20 tpm_buf_destroy(&buf); =20 - if (rc) - goto out; + if (rc =3D=3D TPM2_RC_SUCCESS) { + chip->auth =3D auth; + return 0; + } =20 - out: +out: + kfree_sensitive(auth); return rc; } EXPORT_SYMBOL(tpm2_start_auth_session); @@ -1367,10 +1380,6 @@ int tpm2_sessions_init(struct tpm_chip *chip) return rc; } =20 - chip->auth =3D kmalloc(sizeof(*chip->auth), GFP_KERNEL); - if (!chip->auth) - return -ENOMEM; - return rc; } #endif /* CONFIG_TCG_TPM2_HMAC */ --=20 2.47.0