From 124bdcf4a697f9672d1150de60c5ea489bcad201 Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Sun, 7 May 2017 20:50:02 +0300 Subject: 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 Reviewed-by: Jason Gunthorpe --- drivers/char/tpm/tpm-interface.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) (limited to 'drivers/char/tpm/tpm-interface.c') diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 4ed08ab4d2a8..be5415923886 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -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); -- cgit v1.2.3