On 02/01/2017 11:23 PM, Jarkko Sakkinen wrote:
> There are two type issues associated with tpm_getcap().
>
> You must not do arithmetic with __be32 or __le32 types because sometimes
> it results incorrect results. Calculations must be done only with data
> that is in CPU byte order. This commit migrates tpm_getcap() to struct
> tpm_buf in order to sort out these issues.
>
> The second issue is with struct cap_t as the size of the type bool is
> assumed to be one byte. This commit sorts out the issue by changing the
> type to u8.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
> ---
> v2:
> - Use struct tpm_buf.
> - Merge the type change of 'owned' to this patch.
> drivers/char/tpm/tpm-interface.c | 33 ++++++++++++++++++---------------
> drivers/char/tpm/tpm.h | 15 +--------------
> 2 files changed, 19 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c
> b/drivers/char/tpm/tpm-interface.c
> index 423938e..7af1e8c 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -480,31 +480,34 @@ static const struct tpm_input_header tpm_getcap_header
> = {
> ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
> const char *desc, size_t min_cap_length)
> {
> - struct tpm_cmd_t tpm_cmd;
> + struct tpm_buf buf;
> int rc;
>
> - tpm_cmd.header.in = tpm_getcap_header;
> + rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
I think there is a problem here of twice converting to be32 for both tag
and ordinal.
Both TPM_ORD_GET_CAP and TPM_TAG_RQU_COMMAND are already defined as:
#define TPM_ORD_GET_CAP cpu_to_be32(101)
#define TPM_TAG_RQU_COMMAND cpu_to_be16(193)
and again converted to BE in tpm_buf_init().
Thanks & Regards,
- Nayna
> + if (rc)
> + return rc;
> +
> if (subcap_id == TPM_CAP_VERSION_1_1 ||
> subcap_id == TPM_CAP_VERSION_1_2) {
> - tpm_cmd.params.getcap_in.cap = cpu_to_be32(subcap_id);
> - /*subcap field not necessary */
> - tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
> - tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
> + tpm_buf_append_u32(&buf, subcap_id);
> + tpm_buf_append_u32(&buf, 0);
> } else {
> if (subcap_id == TPM_CAP_FLAG_PERM ||
> subcap_id == TPM_CAP_FLAG_VOL)
> - tpm_cmd.params.getcap_in.cap =
> - cpu_to_be32(TPM_CAP_FLAG);
> + tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
> else
> - tpm_cmd.params.getcap_in.cap =
> - cpu_to_be32(TPM_CAP_PROP);
> - tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> - tpm_cmd.params.getcap_in.subcap = cpu_to_be32(subcap_id);
> + tpm_buf_append_u32(&buf, TPM_CAP_PROP);
> +
> + tpm_buf_append_u32(&buf, 4);
> + tpm_buf_append_u32(&buf, subcap_id);
> }
> - rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> - min_cap_length, 0, desc);
> +
> + rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, min_cap_length, 0,
> + desc);
> if (!rc)
> - *cap = tpm_cmd.params.getcap_out.cap;
> + *cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
> +
> + tpm_buf_destroy(&buf);
> return rc;
> }
> EXPORT_SYMBOL_GPL(tpm_getcap);
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index bff37be..709e7d4 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -281,7 +281,7 @@ struct permanent_flags_t {
> typedef union {
> struct permanent_flags_t perm_flags;
> struct stclear_flags_t stclear_flags;
> - bool owned;
> + u8 owned;
> __be32 num_pcrs;
> struct tpm_version_t tpm_version;
> struct tpm_version_1_2_t tpm_version_1_2;
> @@ -307,17 +307,6 @@ enum tpm_sub_capabilities {
> TPM_CAP_PROP_TIS_DURATION = 0x120,
> };
>
> -struct tpm_getcap_params_in {
> - __be32 cap;
> - __be32 subcap_size;
> - __be32 subcap;
> -} __packed;
> -
> -struct tpm_getcap_params_out {
> - __be32 cap_size;
> - cap_t cap;
> -} __packed;
> -
> struct tpm_readpubek_params_out {
> u8 algorithm[4];
> u8 encscheme[2];
> @@ -367,10 +356,8 @@ struct tpm_startup_in {
> } __packed;
>
> typedef union {
> - struct tpm_getcap_params_out getcap_out;
> struct tpm_readpubek_params_out readpubek_out;
> u8 readpubek_out_buffer[sizeof(struct tpm_readpubek_params_out)];
> - struct tpm_getcap_params_in getcap_in;
> struct tpm_pcrread_in pcrread_in;
> struct tpm_pcrread_out pcrread_out;
> struct tpm_pcrextend_in pcrextend_in;
>
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