From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roberto Sassu Subject: [PATCH v2 3/3] tpm: move TPM 1.2 code of tpm_pcr_extend() to tpm1_pcr_extend() Date: Wed, 3 May 2017 18:19:11 +0200 Message-ID: <20170503161911.17606-4-roberto.sassu@huawei.com> References: <20170503161911.17606-1-roberto.sassu@huawei.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20170503161911.17606-1-roberto.sassu@huawei.com> Sender: owner-linux-security-module@vger.kernel.org To: tpmdd-devel@lists.sourceforge.net Cc: linux-ima-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Roberto Sassu List-Id: tpmdd-devel@lists.sourceforge.net In preparation of the modifications to tpm_pcr_extend(), which will allow callers to supply a digest for each PCR bank of a TPM 2.0, the TPM 1.2 specific code has been moved to tpm1_pcr_extend(). tpm1_pcr_extend() uses tpm_buf_init() to prepare the command buffer, which offers protection against buffer overflow. It is called by tpm_pcr_extend() and tpm_pm_suspend(). Signed-off-by: Roberto Sassu --- drivers/char/tpm/tpm-interface.c | 41 +++++++++++++++++++++++----------------- 1 file changed, 24 insertions(+), 17 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index a8351dd..0277b99 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -774,6 +774,25 @@ static const struct tpm_input_header pcrextend_header = { .ordinal = cpu_to_be32(TPM_ORD_PCR_EXTEND) }; +static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash, + char *log_msg) +{ + struct tpm_buf buf; + int rc; + + rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND); + if (rc) + return rc; + + tpm_buf_append_u32(&buf, pcr_idx); + tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE); + + rc = tpm_transmit_cmd(chip, buf.data, EXTEND_PCR_RESULT_SIZE, + EXTEND_PCR_RESULT_BODY_SIZE, 0, log_msg); + tpm_buf_destroy(&buf); + return rc; +} + /** * tpm_pcr_extend - extend pcr value with hash * @chip_num: tpm idx # or AN& @@ -786,7 +805,6 @@ static const struct tpm_input_header pcrextend_header = { */ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) { - struct tpm_cmd_t cmd; int rc; struct tpm_chip *chip; struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)]; @@ -812,13 +830,8 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) return rc; } - cmd.header.in = pcrextend_header; - cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx); - memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE); - rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, - EXTEND_PCR_RESULT_BODY_SIZE, 0, - "attempting extend a PCR value"); - + rc = tpm1_pcr_extend(chip, pcr_idx, hash, + "attempting extend a PCR value"); tpm_put_ops(chip); return rc; } @@ -1017,15 +1030,9 @@ int tpm_pm_suspend(struct device *dev) } /* for buggy tpm, flush pcrs with extend to selected dummy */ - if (tpm_suspend_pcr) { - cmd.header.in = pcrextend_header; - cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr); - memcpy(cmd.params.pcrextend_in.hash, dummy_hash, - TPM_DIGEST_SIZE); - rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, - EXTEND_PCR_RESULT_BODY_SIZE, 0, - "extending dummy pcr before suspend"); - } + if (tpm_suspend_pcr) + rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash, + "extending dummy pcr before suspend"); /* now do the actual savestate */ for (try = 0; try < TPM_RETRY; try++) { -- 2.9.3