On Tue, May 02, 2017 at 02:31:51PM +0200, Roberto Sassu wrote:
> 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 <roberto.sa...@huawei.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
/Jarkko
> ---
> drivers/char/tpm/tpm-interface.c | 46
> +++++++++++++++++++++-------------------
> 1 file changed, 24 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c
> b/drivers/char/tpm/tpm-interface.c
> index 5c2c032..9059f67 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -763,11 +763,25 @@ EXPORT_SYMBOL_GPL(tpm_pcr_read);
>
> #define EXTEND_PCR_RESULT_SIZE 34
> #define EXTEND_PCR_RESULT_BODY_SIZE 20
> -static const struct tpm_input_header pcrextend_header = {
> - .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
> - .length = cpu_to_be32(34),
> - .ordinal = cpu_to_be32(TPM_ORD_PCREXTEND)
> -};
> +
> +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_PCREXTEND);
> + 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
> @@ -781,7 +795,6 @@ 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)];
> @@ -807,13 +820,8 @@ 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;
> }
> @@ -1011,15 +1019,9 @@ 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
>
> --
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