[PATCH 10/14] platform/x86/intel/ifs: Add metadata validation

Jithu Joseph
2022-10-21T20:41:16Z

The data portion of IFS test image file contains a meta-data
structure in addition to test data and hashes.

Introduce the layout of this meta_data structure and validate
the sanity of certain fields of the new-image before loading.

Tweak references to IFS test image chunks to reflect the updated
layout of the test image.

Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
---
drivers/platform/x86/intel/ifs/ifs.h | 2 +
drivers/platform/x86/intel/ifs/load.c | 54 +++++++++++++++++++++++++++
2 files changed, 56 insertions(+)

diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
index be37512535f2..bb43fd65d2d2 100644
--- a/drivers/platform/x86/intel/ifs/ifs.h
+++ b/drivers/platform/x86/intel/ifs/ifs.h
@@ -196,6 +196,7 @@ union ifs_status {
* @valid_chunks: number of chunks which could be validated.
* @status: it holds simple status pass/fail/untested
* @scan_details: opaque scan status code from h/w
+ * @cur_batch: suffix indicating the currently loaded test file
*/
struct ifs_data {
int integrity_cap_bit;
@@ -205,6 +206,7 @@ struct ifs_data {
int valid_chunks;
int status;
u64 scan_details;
+ int cur_batch;
};

struct ifs_work {
diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
index 3cb13a7aa74b..d300cf3ce5bd 100644
--- a/drivers/platform/x86/intel/ifs/load.c
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -8,8 +8,24 @@

#include "ifs.h"

+struct meta_data {
+ unsigned int meta_type; // metadata type
+ unsigned int meta_size; // size of this entire struct including hdrs.
+ unsigned int test_type; // IFS test type
+ unsigned int fusa_info; // Fusa info
+ unsigned int total_images; // Total number of images
+ unsigned int current_image; // Current Image #
+ unsigned int total_chunks; // Total number of chunks in this image
+ unsigned int starting_chunk; // Starting chunk number in this image
+ unsigned int size_per_chunk; // size of each chunk
+ unsigned int chunks_per_stride; // number of chunks in a stride
+ unsigned int reserved[54]; // Align to 256 bytes for chunk alignment.
+};
+
#define IFS_HEADER_SIZE (sizeof(struct microcode_header_intel))
#define IFS_HEADER_VER 2
+#define META_TYPE_IFS 1
+#define IFS_CHUNK_ALIGNMENT 256
static struct microcode_header_intel *ifs_header_ptr; /* pointer to the ifs image header */
static u64 ifs_hash_ptr; /* Address of ifs metadata (hash) */
static u64 ifs_test_image_ptr; /* 256B aligned address of test pattern */
@@ -98,6 +114,41 @@ static void copy_hashes_authenticate_chunks(struct work_struct *work)
complete(&ifs_done);
}

+static int validate_ifs_metadata(struct device *dev)
+{
+ struct ifs_data *ifsd = ifs_get_data(dev);
+ struct meta_data *ifs_meta;
+ char test_file[64];
+ int ret = -EINVAL;
+
+ snprintf(test_file, sizeof(test_file), "%02x-%02x-%02x-%02x.scan",
+ boot_cpu_data.x86, boot_cpu_data.x86_model,
+ boot_cpu_data.x86_stepping, ifsd->cur_batch);
+
+ ifs_meta = (struct meta_data *)microcode_intel_find_meta_data(ifs_header_ptr,
+ META_TYPE_IFS);
+ if (!ifs_meta) {
+ dev_err(dev, "IFS Metadata missing in file %s\n", test_file);
+ return ret;
+ }
+
+ ifs_test_image_ptr = (u64)ifs_meta + sizeof(struct meta_data);
+
+ /* Scan chunk start must be 256 byte aligned */
+ if (!IS_ALIGNED(ifs_test_image_ptr, IFS_CHUNK_ALIGNMENT)) {
+ dev_err(dev, "Scan pattern offset is not 256 byte aligned in %s\n", test_file);
+ return ret;
+ }
+
+ if (ifs_meta->current_image != ifsd->cur_batch) {
+ dev_warn(dev, "Suffix metadata is not matching with filename %s(0x%02x)\n",
+ test_file, ifs_meta->current_image);
+ return ret;
+ }
+
+ return 0;
+}
+
/*
* IFS requires scan chunks authenticated per each socket in the platform.
* Once the test chunk is authenticated, it is automatically copied to secured memory
@@ -114,6 +165,9 @@ static int scan_chunks_sanity_check(struct device *dev)
if (!package_authenticated)
return ret;

+ ret = validate_ifs_metadata(dev);
+ if (ret)
+ return ret;

ifsd->loading_error = false;
ifsd->loaded_version = ifs_header_ptr->rev;
--
2.25.1