feat(drtm): validate launch features in DRTM parameters

Perform sanity checks on the launch features received via DRTM parameters.
Return INVALID_PARAMETERS if they are incorrect.

Change-Id: I7e8068154028d1c8f6b6b45449616bb5711ea76e
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
This commit is contained in:
Manish V Badarkhe 2025-03-06 15:45:18 +00:00
parent af1dd6e1a5
commit 8666bcfa75
2 changed files with 64 additions and 3 deletions

View file

@ -14,6 +14,8 @@
#ifndef ARM_DRTM_SVC_H
#define ARM_DRTM_SVC_H
#include <lib/utils_def.h>
/*
* SMC function IDs for DRTM Service
* Upper word bits set: Fast call, SMC64, Standard Secure Svc. Call (OEN = 4)
@ -239,6 +241,21 @@
<< ARM_DRTM_REGION_SIZE_TYPE_4K_PAGE_NUM_SHIFT)); \
} while (false)
#define DRTM_LAUNCH_FEAT_DLME_IMG_AUTH_SHIFT U(6)
#define DRTM_LAUNCH_FEAT_MEM_PROTECTION_TYPE_SHIFT U(3)
#define DRTM_LAUNCH_FEAT_PCR_USAGE_SCHEMA_SHIFT U(1)
#define DRTM_LAUNCH_FEAT_HASHING_TYPE_SHIFT U(0)
#define DRTM_LAUNCH_FEAT_DLME_IMG_AUTH_MASK U(0x1)
#define DRTM_LAUNCH_FEAT_MEM_PROTECTION_TYPE_MASK U(0x7)
#define DRTM_LAUNCH_FEAT_PCR_USAGE_SCHEMA_MASK U(0x3)
#define DRTM_LAUNCH_FEAT_HASHING_TYPE_MASK U(0x1)
#define DLME_IMG_AUTH U(0x1)
#define REG_MEM_PROTECTION_TYPE U(0x1)
#define DLME_AUTH_SCHEMA U(0x1)
#define TPM_BASED_HASHING U(0x1)
/* Initialization routine for the DRTM service */
int drtm_setup(void);

View file

@ -34,6 +34,8 @@ static drtm_features_t plat_drtm_features;
/* DRTM-formatted memory map. */
static drtm_memory_region_descriptor_table_t *plat_drtm_mem_map;
static const plat_drtm_dma_prot_features_t *plat_dma_prot_feat;
static const plat_drtm_tpm_features_t *plat_tpm_feat;
/* DLME header */
struct_dlme_data_header dlme_data_hdr_init;
@ -44,8 +46,6 @@ uint64_t dlme_data_min_size;
int drtm_setup(void)
{
bool rc;
const plat_drtm_tpm_features_t *plat_tpm_feat;
const plat_drtm_dma_prot_features_t *plat_dma_prot_feat;
INFO("DRTM service setup\n");
@ -322,6 +322,43 @@ static enum drtm_retc drtm_dl_prepare_dlme_data(const struct_drtm_dl_args *args)
return SUCCESS;
}
/* Function to check if the value is valid for each bit field */
static int drtm_dl_check_features_sanity(uint32_t val)
{
/**
* Ensure that if DLME Authorities Schema (Bits [2:1]) is set, then
* DLME image authentication (Bit[6]) must also be set
*/
if ((EXTRACT_FIELD(val, DRTM_LAUNCH_FEAT_PCR_USAGE_SCHEMA_MASK,
DRTM_LAUNCH_FEAT_PCR_USAGE_SCHEMA_SHIFT) == DLME_AUTH_SCHEMA) &&
(EXTRACT_FIELD(val, DRTM_LAUNCH_FEAT_DLME_IMG_AUTH_MASK,
DRTM_LAUNCH_FEAT_DLME_IMG_AUTH_SHIFT) != DLME_IMG_AUTH)) {
return INVALID_PARAMETERS;
}
/**
* Check if Bits [5:3] (Memory protection type) matches with platform's
* memory protection type
*/
if (EXTRACT_FIELD(val, DRTM_LAUNCH_FEAT_MEM_PROTECTION_TYPE_MASK,
DRTM_LAUNCH_FEAT_MEM_PROTECTION_TYPE_SHIFT) !=
__builtin_ctz(plat_dma_prot_feat->dma_protection_support)) {
return INVALID_PARAMETERS;
}
/**
* Check if Bits [0] (Type of hashing) matches with platform's
* supported hash type.
*/
if (EXTRACT_FIELD(val, DRTM_LAUNCH_FEAT_HASHING_TYPE_MASK,
DRTM_LAUNCH_FEAT_HASHING_TYPE_SHIFT) !=
plat_tpm_feat->tpm_based_hash_support) {
return INVALID_PARAMETERS;
}
return 0;
}
/*
* Note: accesses to the dynamic launch args, and to the DLME data are
* little-endian as required, thanks to TF-A BL31 init requirements.
@ -369,7 +406,7 @@ static enum drtm_retc drtm_dl_check_args(uint64_t x1,
args_buf = *a;
rc = mmap_remove_dynamic_region(va_mapping, va_mapping_size);
if (rc) {
if (rc != 0) {
ERROR("%s(): mmap_remove_dynamic_region() failed unexpectedly"
" rc=%d\n", __func__, rc);
panic();
@ -383,6 +420,13 @@ static enum drtm_retc drtm_dl_check_args(uint64_t x1,
return NOT_SUPPORTED;
}
rc = drtm_dl_check_features_sanity(a->features);
if (rc != 0) {
ERROR("%s(): drtm_dl_check_features_sanity() failed.\n"
" rc=%d\n", __func__, rc);
return rc;
}
if (!(a->dlme_img_off < a->dlme_size &&
a->dlme_data_off < a->dlme_size)) {
ERROR("DRTM: argument offset is outside of the DLME region\n");