tpm: fix byte order related arithmetic inconsistency in tpm_getcap()

You should not do arithmetic with __be32 or __le32 types because
sometimes it results incorrect results. Calculations must be done only
with integers that are in in the CPU byte order. This commit migrates
tpm_getcap() to struct tpm_buf in order to sort out these issues.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
This commit is contained in:
Jarkko Sakkinen 2017-05-07 20:50:02 +03:00
parent d8c3eab5cb
commit 124bdcf4a6
2 changed files with 16 additions and 27 deletions

View File

@ -552,31 +552,33 @@ 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);
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, NULL, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
rc = tpm_transmit_cmd(chip, NULL, 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);

View File

@ -339,17 +339,6 @@ 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];
@ -399,10 +388,8 @@ 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;