in lib/libavb/avb_slot_verify.c [540:1219]
static AvbSlotVerifyResult load_and_verify_vbmeta(
AvbOps* ops,
const char* const* requested_partitions,
const char* ab_suffix,
AvbSlotVerifyFlags flags,
bool allow_verification_error,
AvbVBMetaImageFlags toplevel_vbmeta_flags,
int rollback_index_location,
const char* partition_name,
size_t partition_name_len,
const uint8_t* expected_public_key,
size_t expected_public_key_length,
AvbSlotVerifyData* slot_data,
AvbAlgorithmType* out_algorithm_type,
AvbCmdlineSubstList* out_additional_cmdline_subst) {
char full_partition_name[AVB_PART_NAME_MAX_SIZE];
AvbSlotVerifyResult ret;
AvbIOResult io_ret;
size_t vbmeta_offset;
size_t vbmeta_size;
uint8_t* vbmeta_buf = NULL;
size_t vbmeta_num_read;
AvbVBMetaVerifyResult vbmeta_ret;
const uint8_t* pk_data;
size_t pk_len;
AvbVBMetaImageHeader vbmeta_header;
uint64_t stored_rollback_index;
const AvbDescriptor** descriptors = NULL;
size_t num_descriptors;
size_t n;
bool is_main_vbmeta;
bool look_for_vbmeta_footer;
AvbVBMetaData* vbmeta_image_data = NULL;
ret = AVB_SLOT_VERIFY_RESULT_OK;
avb_assert(slot_data != NULL);
/* Since we allow top-level vbmeta in 'boot', use
* rollback_index_location to determine whether we're the main
* vbmeta struct.
*/
is_main_vbmeta = false;
if (rollback_index_location == 0) {
if ((flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) == 0) {
is_main_vbmeta = true;
}
}
/* Don't use footers for vbmeta partitions ('vbmeta' or
* 'vbmeta_<partition_name>').
*/
look_for_vbmeta_footer = true;
if (avb_strncmp(partition_name, "vbmeta", avb_strlen("vbmeta")) == 0) {
look_for_vbmeta_footer = false;
}
if (!avb_validate_utf8((const uint8_t*)partition_name, partition_name_len)) {
avb_error("Partition name is not valid UTF-8.\n");
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
/* Construct full partition name e.g. system_a. */
if (!avb_str_concat(full_partition_name,
sizeof full_partition_name,
partition_name,
partition_name_len,
ab_suffix,
avb_strlen(ab_suffix))) {
avb_error("Partition name and suffix does not fit.\n");
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
/* If we're loading from the main vbmeta partition, the vbmeta struct is in
* the beginning. Otherwise we may have to locate it via a footer... if no
* footer is found, we look in the beginning to support e.g. vbmeta_<org>
* partitions holding data for e.g. super partitions (b/80195851 for
* rationale).
*/
vbmeta_offset = 0;
vbmeta_size = VBMETA_MAX_SIZE;
if (look_for_vbmeta_footer) {
uint8_t footer_buf[AVB_FOOTER_SIZE];
size_t footer_num_read;
AvbFooter footer;
io_ret = ops->read_from_partition(ops,
full_partition_name,
-AVB_FOOTER_SIZE,
AVB_FOOTER_SIZE,
footer_buf,
&footer_num_read);
if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
} else if (io_ret != AVB_IO_RESULT_OK) {
avb_errorv(full_partition_name, ": Error loading footer.\n", NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
goto out;
}
avb_assert(footer_num_read == AVB_FOOTER_SIZE);
if (!avb_footer_validate_and_byteswap((const AvbFooter*)footer_buf,
&footer)) {
avb_debugv(full_partition_name, ": No footer detected.\n", NULL);
} else {
/* Basic footer sanity check since the data is untrusted. */
if (footer.vbmeta_size > VBMETA_MAX_SIZE) {
avb_errorv(
full_partition_name, ": Invalid vbmeta size in footer.\n", NULL);
} else {
vbmeta_offset = footer.vbmeta_offset;
vbmeta_size = footer.vbmeta_size;
}
}
}
vbmeta_buf = avb_malloc(vbmeta_size);
if (vbmeta_buf == NULL) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
if (vbmeta_offset != 0) {
avb_debugv("Loading vbmeta struct in footer from partition '",
full_partition_name,
"'.\n",
NULL);
} else {
avb_debugv("Loading vbmeta struct from partition '",
full_partition_name,
"'.\n",
NULL);
}
io_ret = ops->read_from_partition(ops,
full_partition_name,
vbmeta_offset,
vbmeta_size,
vbmeta_buf,
&vbmeta_num_read);
if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
} else if (io_ret != AVB_IO_RESULT_OK) {
/* If we're looking for 'vbmeta' but there is no such partition,
* go try to get it from the boot partition instead.
*/
if (is_main_vbmeta && io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION &&
!look_for_vbmeta_footer) {
avb_debugv(full_partition_name,
": No such partition. Trying 'boot' instead.\n",
NULL);
ret = load_and_verify_vbmeta(ops,
requested_partitions,
ab_suffix,
flags,
allow_verification_error,
0 /* toplevel_vbmeta_flags */,
0 /* rollback_index_location */,
"boot",
avb_strlen("boot"),
NULL /* expected_public_key */,
0 /* expected_public_key_length */,
slot_data,
out_algorithm_type,
out_additional_cmdline_subst);
goto out;
} else {
avb_errorv(full_partition_name, ": Error loading vbmeta data.\n", NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
goto out;
}
}
avb_assert(vbmeta_num_read <= vbmeta_size);
/* Check if the image is properly signed and get the public key used
* to sign the image.
*/
vbmeta_ret =
avb_vbmeta_image_verify(vbmeta_buf, vbmeta_num_read, &pk_data, &pk_len);
switch (vbmeta_ret) {
case AVB_VBMETA_VERIFY_RESULT_OK:
avb_assert(pk_data != NULL && pk_len > 0);
break;
case AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED:
case AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH:
case AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH:
ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION;
avb_errorv(full_partition_name,
": Error verifying vbmeta image: ",
avb_vbmeta_verify_result_to_string(vbmeta_ret),
"\n",
NULL);
if (!allow_verification_error) {
goto out;
}
break;
case AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER:
/* No way to continue this case. */
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
avb_errorv(full_partition_name,
": Error verifying vbmeta image: invalid vbmeta header\n",
NULL);
goto out;
case AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION:
/* No way to continue this case. */
ret = AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION;
avb_errorv(full_partition_name,
": Error verifying vbmeta image: unsupported AVB version\n",
NULL);
goto out;
}
/* Byteswap the header. */
avb_vbmeta_image_header_to_host_byte_order((AvbVBMetaImageHeader*)vbmeta_buf,
&vbmeta_header);
/* If we're the toplevel, assign flags so they'll be passed down. */
if (is_main_vbmeta) {
toplevel_vbmeta_flags = (AvbVBMetaImageFlags)vbmeta_header.flags;
} else {
if (vbmeta_header.flags != 0) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
avb_errorv(full_partition_name,
": chained vbmeta image has non-zero flags\n",
NULL);
goto out;
}
}
uint32_t rollback_index_location_to_use = rollback_index_location;
/* Check if key used to make signature matches what is expected. */
if (pk_data != NULL) {
if (expected_public_key != NULL) {
avb_assert(!is_main_vbmeta);
if (expected_public_key_length != pk_len ||
avb_safe_memcmp(expected_public_key, pk_data, pk_len) != 0) {
avb_errorv(full_partition_name,
": Public key used to sign data does not match key in chain "
"partition descriptor.\n",
NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED;
if (!allow_verification_error) {
goto out;
}
}
} else {
bool key_is_trusted = false;
const uint8_t* pk_metadata = NULL;
size_t pk_metadata_len = 0;
if (vbmeta_header.public_key_metadata_size > 0) {
pk_metadata = vbmeta_buf + sizeof(AvbVBMetaImageHeader) +
vbmeta_header.authentication_data_block_size +
vbmeta_header.public_key_metadata_offset;
pk_metadata_len = vbmeta_header.public_key_metadata_size;
}
// If we're not using a vbmeta partition, need to use another AvbOps...
if (flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) {
io_ret = ops->validate_public_key_for_partition(
ops,
full_partition_name,
pk_data,
pk_len,
pk_metadata,
pk_metadata_len,
&key_is_trusted,
&rollback_index_location_to_use);
} else {
avb_assert(is_main_vbmeta);
io_ret = ops->validate_vbmeta_public_key(ops,
pk_data,
pk_len,
pk_metadata,
pk_metadata_len,
&key_is_trusted);
}
if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
} else if (io_ret != AVB_IO_RESULT_OK) {
avb_errorv(full_partition_name,
": Error while checking public key used to sign data.\n",
NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
goto out;
}
if (!key_is_trusted) {
avb_errorv(full_partition_name,
": Public key used to sign data rejected.\n",
NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED;
if (!allow_verification_error) {
goto out;
}
}
}
}
/* Check rollback index. */
io_ret = ops->read_rollback_index(
ops, rollback_index_location_to_use, &stored_rollback_index);
if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
} else if (io_ret != AVB_IO_RESULT_OK) {
avb_errorv(full_partition_name,
": Error getting rollback index for location.\n",
NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
goto out;
}
if (vbmeta_header.rollback_index < stored_rollback_index) {
avb_errorv(
full_partition_name,
": Image rollback index is less than the stored rollback index.\n",
NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX;
if (!allow_verification_error) {
goto out;
}
}
/* Copy vbmeta to vbmeta_images before recursing. */
if (is_main_vbmeta) {
avb_assert(slot_data->num_vbmeta_images == 0);
} else {
if (!(flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION)) {
avb_assert(slot_data->num_vbmeta_images > 0);
}
}
if (slot_data->num_vbmeta_images == MAX_NUMBER_OF_VBMETA_IMAGES) {
avb_errorv(full_partition_name, ": Too many vbmeta images.\n", NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
vbmeta_image_data = &slot_data->vbmeta_images[slot_data->num_vbmeta_images++];
vbmeta_image_data->partition_name = avb_strdup(partition_name);
vbmeta_image_data->vbmeta_data = vbmeta_buf;
/* Note that |vbmeta_buf| is actually |vbmeta_num_read| bytes long
* and this includes data past the end of the image. Pass the
* actual size of the vbmeta image. Also, no need to use
* avb_safe_add() since the header has already been verified.
*/
vbmeta_image_data->vbmeta_size =
sizeof(AvbVBMetaImageHeader) +
vbmeta_header.authentication_data_block_size +
vbmeta_header.auxiliary_data_block_size;
vbmeta_image_data->verify_result = vbmeta_ret;
/* If verification has been disabled by setting a bit in the image,
* we're done... except that we need to load the entirety of the
* requested partitions.
*/
if (vbmeta_header.flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) {
AvbSlotVerifyResult sub_ret;
avb_debugv(
full_partition_name, ": VERIFICATION_DISABLED bit is set.\n", NULL);
/* If load_requested_partitions() fail it is always a fatal
* failure (e.g. ERROR_INVALID_ARGUMENT, ERROR_OOM, etc.) rather
* than recoverable (e.g. one where result_should_continue()
* returns true) and we want to convey that error.
*/
sub_ret = load_requested_partitions(
ops, requested_partitions, ab_suffix, slot_data);
if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) {
ret = sub_ret;
}
goto out;
}
/* Now go through all descriptors and take the appropriate action:
*
* - hash descriptor: Load data from partition, calculate hash, and
* checks that it matches what's in the hash descriptor.
*
* - hashtree descriptor: Do nothing since verification happens
* on-the-fly from within the OS. (Unless the descriptor uses a
* persistent digest, in which case we need to find it).
*
* - chained partition descriptor: Load the footer, load the vbmeta
* image, verify vbmeta image (includes rollback checks, hash
* checks, bail on chained partitions).
*/
descriptors =
avb_descriptor_get_all(vbmeta_buf, vbmeta_num_read, &num_descriptors);
for (n = 0; n < num_descriptors; n++) {
AvbDescriptor desc;
if (!avb_descriptor_validate_and_byteswap(descriptors[n], &desc)) {
avb_errorv(full_partition_name, ": Descriptor is invalid.\n", NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
switch (desc.tag) {
case AVB_DESCRIPTOR_TAG_HASH: {
AvbSlotVerifyResult sub_ret;
sub_ret = load_and_verify_hash_partition(ops,
requested_partitions,
ab_suffix,
allow_verification_error,
descriptors[n],
slot_data);
if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) {
ret = sub_ret;
if (!allow_verification_error || !result_should_continue(ret)) {
goto out;
}
}
} break;
case AVB_DESCRIPTOR_TAG_CHAIN_PARTITION: {
AvbSlotVerifyResult sub_ret;
AvbChainPartitionDescriptor chain_desc;
const uint8_t* chain_partition_name;
const uint8_t* chain_public_key;
/* Only allow CHAIN_PARTITION descriptors in the main vbmeta image. */
if (!is_main_vbmeta) {
avb_errorv(full_partition_name,
": Encountered chain descriptor not in main image.\n",
NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
if (!avb_chain_partition_descriptor_validate_and_byteswap(
(AvbChainPartitionDescriptor*)descriptors[n], &chain_desc)) {
avb_errorv(full_partition_name,
": Chain partition descriptor is invalid.\n",
NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
if (chain_desc.rollback_index_location == 0) {
avb_errorv(full_partition_name,
": Chain partition has invalid "
"rollback_index_location field.\n",
NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
chain_partition_name = ((const uint8_t*)descriptors[n]) +
sizeof(AvbChainPartitionDescriptor);
chain_public_key = chain_partition_name + chain_desc.partition_name_len;
sub_ret =
load_and_verify_vbmeta(ops,
requested_partitions,
ab_suffix,
flags,
allow_verification_error,
toplevel_vbmeta_flags,
chain_desc.rollback_index_location,
(const char*)chain_partition_name,
chain_desc.partition_name_len,
chain_public_key,
chain_desc.public_key_len,
slot_data,
NULL, /* out_algorithm_type */
NULL /* out_additional_cmdline_subst */);
if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) {
ret = sub_ret;
if (!result_should_continue(ret)) {
goto out;
}
}
} break;
case AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE: {
const uint8_t* kernel_cmdline;
AvbKernelCmdlineDescriptor kernel_cmdline_desc;
bool apply_cmdline;
if (!avb_kernel_cmdline_descriptor_validate_and_byteswap(
(AvbKernelCmdlineDescriptor*)descriptors[n],
&kernel_cmdline_desc)) {
avb_errorv(full_partition_name,
": Kernel cmdline descriptor is invalid.\n",
NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
kernel_cmdline = ((const uint8_t*)descriptors[n]) +
sizeof(AvbKernelCmdlineDescriptor);
if (!avb_validate_utf8(kernel_cmdline,
kernel_cmdline_desc.kernel_cmdline_length)) {
avb_errorv(full_partition_name,
": Kernel cmdline is not valid UTF-8.\n",
NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
/* Compare the flags for top-level VBMeta struct with flags in
* the command-line descriptor so command-line snippets only
* intended for a certain mode (dm-verity enabled/disabled)
* are skipped if applicable.
*/
apply_cmdline = true;
if (toplevel_vbmeta_flags & AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED) {
if (kernel_cmdline_desc.flags &
AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED) {
apply_cmdline = false;
}
} else {
if (kernel_cmdline_desc.flags &
AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_DISABLED) {
apply_cmdline = false;
}
}
if (apply_cmdline) {
if (slot_data->cmdline == NULL) {
slot_data->cmdline =
avb_calloc(kernel_cmdline_desc.kernel_cmdline_length + 1);
if (slot_data->cmdline == NULL) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
avb_memcpy(slot_data->cmdline,
kernel_cmdline,
kernel_cmdline_desc.kernel_cmdline_length);
} else {
/* new cmdline is: <existing_cmdline> + ' ' + <newcmdline> + '\0' */
size_t orig_size = avb_strlen(slot_data->cmdline);
size_t new_size =
orig_size + 1 + kernel_cmdline_desc.kernel_cmdline_length + 1;
char* new_cmdline = avb_calloc(new_size);
if (new_cmdline == NULL) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
avb_memcpy(new_cmdline, slot_data->cmdline, orig_size);
new_cmdline[orig_size] = ' ';
avb_memcpy(new_cmdline + orig_size + 1,
kernel_cmdline,
kernel_cmdline_desc.kernel_cmdline_length);
avb_free(slot_data->cmdline);
slot_data->cmdline = new_cmdline;
}
}
} break;
case AVB_DESCRIPTOR_TAG_HASHTREE: {
AvbHashtreeDescriptor hashtree_desc;
if (!avb_hashtree_descriptor_validate_and_byteswap(
(AvbHashtreeDescriptor*)descriptors[n], &hashtree_desc)) {
avb_errorv(
full_partition_name, ": Hashtree descriptor is invalid.\n", NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
/* We only need to continue when there is no digest in the descriptor.
* This is because the only processing here is to find the digest and
* make it available on the kernel command line.
*/
if (hashtree_desc.root_digest_len == 0) {
char part_name[AVB_PART_NAME_MAX_SIZE];
size_t digest_len = 0;
uint8_t digest_buf[AVB_SHA512_DIGEST_SIZE];
const uint8_t* desc_partition_name =
((const uint8_t*)descriptors[n]) + sizeof(AvbHashtreeDescriptor);
if (!avb_validate_utf8(desc_partition_name,
hashtree_desc.partition_name_len)) {
avb_error("Partition name is not valid UTF-8.\n");
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
/* No ab_suffix for partitions without a digest in the descriptor
* because these partitions hold data unique to this device and are
* not updated using an A/B scheme.
*/
if ((hashtree_desc.flags &
AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB) == 0 &&
avb_strlen(ab_suffix) != 0) {
avb_error("Cannot use A/B with a persistent root digest.\n");
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
if (hashtree_desc.partition_name_len >= AVB_PART_NAME_MAX_SIZE) {
avb_error("Partition name does not fit.\n");
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
avb_memcpy(
part_name, desc_partition_name, hashtree_desc.partition_name_len);
part_name[hashtree_desc.partition_name_len] = '\0';
/* Determine the expected digest size from the hash algorithm. */
if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, "sha1") ==
0) {
digest_len = AVB_SHA1_DIGEST_SIZE;
} else if (avb_strcmp((const char*)hashtree_desc.hash_algorithm,
"sha256") == 0) {
digest_len = AVB_SHA256_DIGEST_SIZE;
} else if (avb_strcmp((const char*)hashtree_desc.hash_algorithm,
"sha512") == 0) {
digest_len = AVB_SHA512_DIGEST_SIZE;
} else {
avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
ret = read_persistent_digest(ops,
part_name,
digest_len,
NULL /* initial_digest */,
digest_buf);
if (ret != AVB_SLOT_VERIFY_RESULT_OK) {
goto out;
}
if (out_additional_cmdline_subst) {
ret =
avb_add_root_digest_substitution(part_name,
digest_buf,
digest_len,
out_additional_cmdline_subst);
if (ret != AVB_SLOT_VERIFY_RESULT_OK) {
goto out;
}
}
}
} break;
case AVB_DESCRIPTOR_TAG_PROPERTY:
/* Do nothing. */
break;
}
}
if (rollback_index_location < 0 ||
rollback_index_location >= AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS) {
avb_errorv(
full_partition_name, ": Invalid rollback_index_location.\n", NULL);
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
goto out;
}
slot_data->rollback_indexes[rollback_index_location] =
vbmeta_header.rollback_index;
if (out_algorithm_type != NULL) {
*out_algorithm_type = (AvbAlgorithmType)vbmeta_header.algorithm_type;
}
out:
/* If |vbmeta_image_data| isn't NULL it means that it adopted
* |vbmeta_buf| so in that case don't free it here.
*/
if (vbmeta_image_data == NULL) {
if (vbmeta_buf != NULL) {
avb_free(vbmeta_buf);
}
}
if (descriptors != NULL) {
avb_free(descriptors);
}
return ret;
}