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path: root/security/integrity/ima/ima_template.c
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Diffstat (limited to 'security/integrity/ima/ima_template.c')
-rw-r--r--security/integrity/ima/ima_template.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index febd12ed9b55..03803de4226e 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -37,6 +37,7 @@ static struct ima_template_field supported_fields[] = {
{.field_id = "sig", .field_init = ima_eventsig_init,
.field_show = ima_show_template_sig},
};
+#define MAX_TEMPLATE_NAME_LEN 15
static struct ima_template_desc *ima_template;
static struct ima_template_desc *lookup_template_desc(const char *name);
@@ -205,3 +206,179 @@ int __init ima_init_template(void)
return result;
}
+
+static int ima_restore_template_data(struct ima_template_desc *template_desc,
+ void *template_data,
+ int template_data_size,
+ struct ima_template_entry **entry)
+{
+ struct binary_field_data {
+ u32 len;
+ u8 data[0];
+ } __packed;
+
+ struct binary_field_data *field_data;
+ int offset = 0;
+ int ret = 0;
+ int i;
+
+ *entry = kzalloc(sizeof(**entry) +
+ template_desc->num_fields * sizeof(struct ima_field_data),
+ GFP_NOFS);
+ if (!*entry)
+ return -ENOMEM;
+
+ (*entry)->template_desc = template_desc;
+ for (i = 0; i < template_desc->num_fields; i++) {
+ field_data = template_data + offset;
+
+ /* Each field of the template data is prefixed with a length. */
+ if (offset > (template_data_size - sizeof(*field_data))) {
+ pr_err("Restoring the template field failed\n");
+ ret = -EINVAL;
+ break;
+ }
+ offset += sizeof(*field_data);
+
+ if (offset > (template_data_size - field_data->len)) {
+ pr_err("Restoring the template field data failed\n");
+ ret = -EINVAL;
+ break;
+ }
+ offset += field_data->len;
+
+ (*entry)->template_data[i].len = field_data->len;
+ (*entry)->template_data_len += sizeof(field_data->len);
+
+ (*entry)->template_data[i].data =
+ kzalloc(field_data->len + 1, GFP_KERNEL);
+ if (!(*entry)->template_data[i].data) {
+ ret = -ENOMEM;
+ break;
+ }
+ memcpy((*entry)->template_data[i].data, field_data->data,
+ field_data->len);
+ (*entry)->template_data_len += field_data->len;
+ }
+
+ if (ret < 0) {
+ ima_free_template_entry(*entry);
+ *entry = NULL;
+ }
+
+ return ret;
+}
+
+/* Restore the serialized binary measurement list without extending PCRs. */
+int ima_restore_measurement_list(loff_t size, void *buf)
+{
+ struct binary_hdr_v1 {
+ u32 pcr;
+ u8 digest[TPM_DIGEST_SIZE];
+ u32 template_name_len;
+ char template_name[0];
+ } __packed;
+ char template_name[MAX_TEMPLATE_NAME_LEN];
+
+ struct binary_data_v1 {
+ u32 template_data_size;
+ char template_data[0];
+ } __packed;
+
+ struct ima_kexec_hdr *khdr = buf;
+ struct binary_hdr_v1 *hdr_v1;
+ struct binary_data_v1 *data_v1;
+
+ void *bufp = buf + sizeof(*khdr);
+ void *bufendp = buf + khdr->buffer_size;
+ struct ima_template_entry *entry;
+ struct ima_template_desc *template_desc;
+ unsigned long count = 0;
+ int ret = 0;
+
+ if (!buf || size < sizeof(*khdr))
+ return 0;
+
+ if (khdr->version != 1) {
+ pr_err("attempting to restore a incompatible measurement list");
+ return -EINVAL;
+ }
+
+ if (khdr->count > ULONG_MAX - 1) {
+ pr_err("attempting to restore too many measurements");
+ return -EINVAL;
+ }
+
+ /*
+ * ima kexec buffer prefix: version, buffer size, count
+ * v1 format: pcr, digest, template-name-len, template-name,
+ * template-data-size, template-data
+ */
+ while ((bufp < bufendp) && (count++ < khdr->count)) {
+ hdr_v1 = bufp;
+ if (bufp > (bufendp - sizeof(*hdr_v1))) {
+ pr_err("attempting to restore partial measurement\n");
+ ret = -EINVAL;
+ break;
+ }
+ bufp += sizeof(*hdr_v1);
+
+ if ((hdr_v1->template_name_len >= MAX_TEMPLATE_NAME_LEN) ||
+ (bufp > (bufendp - hdr_v1->template_name_len))) {
+ pr_err("attempting to restore a template name \
+ that is too long\n");
+ ret = -EINVAL;
+ break;
+ }
+ data_v1 = bufp += (u_int8_t)hdr_v1->template_name_len;
+
+ /* template name is not null terminated */
+ memcpy(template_name, hdr_v1->template_name,
+ hdr_v1->template_name_len);
+ template_name[hdr_v1->template_name_len] = 0;
+
+ if (strcmp(template_name, "ima") == 0) {
+ pr_err("attempting to restore an unsupported \
+ template \"%s\" failed\n", template_name);
+ ret = -EINVAL;
+ break;
+ }
+
+ /* get template format */
+ template_desc = lookup_template_desc(template_name);
+ if (!template_desc) {
+ pr_err("template \"%s\" not found\n", template_name);
+ ret = -EINVAL;
+ break;
+ }
+
+ if (bufp > (bufendp - sizeof(data_v1->template_data_size))) {
+ pr_err("restoring the template data size failed\n");
+ ret = -EINVAL;
+ break;
+ }
+ bufp += (u_int8_t) sizeof(data_v1->template_data_size);
+
+ if (bufp > (bufendp - data_v1->template_data_size)) {
+ pr_err("restoring the template data failed\n");
+ ret = -EINVAL;
+ break;
+ }
+ bufp += data_v1->template_data_size;
+
+ ret = ima_restore_template_data(template_desc,
+ data_v1->template_data,
+ data_v1->template_data_size,
+ &entry);
+ if (ret < 0)
+ break;
+
+ memcpy(entry->digest, hdr_v1->digest, TPM_DIGEST_SIZE);
+ entry->pcr = hdr_v1->pcr;
+ ret = ima_restore_measurement_entry(entry);
+ if (ret < 0)
+ break;
+
+ }
+ return ret;
+}