1 files changed, 103 insertions, 28 deletions

diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index 111898aad56e..f290f78c3f30 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -35,16 +35,18 @@ static __init bool uefi_check_ignore_db(void)
  * Get a certificate list blob from the named EFI variable.
  */
 static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
-				  unsigned long *size)
+				  unsigned long *size, efi_status_t *status)
 {
-	efi_status_t status;
 	unsigned long lsize = 4;
 	unsigned long tmpdb[4];
 	void *db;
 
-	status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb);
-	if (status != EFI_BUFFER_TOO_SMALL) {
-		pr_err("Couldn't get size: 0x%lx\n", status);
+	*status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb);
+	if (*status == EFI_NOT_FOUND)
+		return NULL;
+
+	if (*status != EFI_BUFFER_TOO_SMALL) {
+		pr_err("Couldn't get size: 0x%lx\n", *status);
 		return NULL;
 	}
 
@@ -52,10 +54,10 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
 	if (!db)
 		return NULL;
 
-	status = efi.get_variable(name, guid, NULL, &lsize, db);
-	if (status != EFI_SUCCESS) {
+	*status = efi.get_variable(name, guid, NULL, &lsize, db);
+	if (*status != EFI_SUCCESS) {
 		kfree(db);
-		pr_err("Error reading db var: 0x%lx\n", status);
+		pr_err("Error reading db var: 0x%lx\n", *status);
 		return NULL;
 	}
 
@@ -64,6 +66,65 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
 }
 
 /*
+ * load_moklist_certs() - Load MokList certs
+ *
+ * Load the certs contained in the UEFI MokListRT database into the
+ * platform trusted keyring.
+ *
+ * This routine checks the EFI MOK config table first. If and only if
+ * that fails, this routine uses the MokListRT ordinary UEFI variable.
+ *
+ * Return:	Status
+ */
+static int __init load_moklist_certs(void)
+{
+	struct efi_mokvar_table_entry *mokvar_entry;
+	efi_guid_t mok_var = EFI_SHIM_LOCK_GUID;
+	void *mok;
+	unsigned long moksize;
+	efi_status_t status;
+	int rc;
+
+	/* First try to load certs from the EFI MOKvar config table.
+	 * It's not an error if the MOKvar config table doesn't exist
+	 * or the MokListRT entry is not found in it.
+	 */
+	mokvar_entry = efi_mokvar_entry_find("MokListRT");
+	if (mokvar_entry) {
+		rc = parse_efi_signature_list("UEFI:MokListRT (MOKvar table)",
+					      mokvar_entry->data,
+					      mokvar_entry->data_size,
+					      get_handler_for_db);
+		/* All done if that worked. */
+		if (!rc)
+			return rc;
+
+		pr_err("Couldn't parse MokListRT signatures from EFI MOKvar config table: %d\n",
+		       rc);
+	}
+
+	/* Get MokListRT. It might not exist, so it isn't an error
+	 * if we can't get it.
+	 */
+	mok = get_cert_list(L"MokListRT", &mok_var, &moksize, &status);
+	if (mok) {
+		rc = parse_efi_signature_list("UEFI:MokListRT",
+					      mok, moksize, get_handler_for_db);
+		kfree(mok);
+		if (rc)
+			pr_err("Couldn't parse MokListRT signatures: %d\n", rc);
+		return rc;
+	}
+	if (status == EFI_NOT_FOUND)
+		pr_debug("MokListRT variable wasn't found\n");
+	else
+		pr_info("Couldn't get UEFI MokListRT\n");
+	return 0;
+}
+
+/*
+ * load_uefi_certs() - Load certs from UEFI sources
+ *
  * Load the certs contained in the UEFI databases into the platform trusted
  * keyring and the UEFI blacklisted X.509 cert SHA256 hashes into the blacklist
  * keyring.
@@ -72,20 +133,24 @@ static int __init load_uefi_certs(void)
 {
 	efi_guid_t secure_var = EFI_IMAGE_SECURITY_DATABASE_GUID;
 	efi_guid_t mok_var = EFI_SHIM_LOCK_GUID;
-	void *db = NULL, *dbx = NULL, *mok = NULL;
-	unsigned long dbsize = 0, dbxsize = 0, moksize = 0;
+	void *db = NULL, *dbx = NULL, *mokx = NULL;
+	unsigned long dbsize = 0, dbxsize = 0, mokxsize = 0;
+	efi_status_t status;
 	int rc = 0;
 
-	if (!efi.get_variable)
+	if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE))
 		return false;
 
-	/* Get db, MokListRT, and dbx.  They might not exist, so it isn't
-	 * an error if we can't get them.
+	/* Get db and dbx.  They might not exist, so it isn't an error
+	 * if we can't get them.
 	 */
 	if (!uefi_check_ignore_db()) {
-		db = get_cert_list(L"db", &secure_var, &dbsize);
+		db = get_cert_list(L"db", &secure_var, &dbsize, &status);
 		if (!db) {
-			pr_err("MODSIGN: Couldn't get UEFI db list\n");
+			if (status == EFI_NOT_FOUND)
+				pr_debug("MODSIGN: db variable wasn't found\n");
+			else
+				pr_err("MODSIGN: Couldn't get UEFI db list\n");
 		} else {
 			rc = parse_efi_signature_list("UEFI:db",
 					db, dbsize, get_handler_for_db);
@@ -96,20 +161,12 @@ static int __init load_uefi_certs(void)
 		}
 	}
 
-	mok = get_cert_list(L"MokListRT", &mok_var, &moksize);
-	if (!mok) {
-		pr_info("Couldn't get UEFI MokListRT\n");
-	} else {
-		rc = parse_efi_signature_list("UEFI:MokListRT",
-					      mok, moksize, get_handler_for_db);
-		if (rc)
-			pr_err("Couldn't parse MokListRT signatures: %d\n", rc);
-		kfree(mok);
-	}
-
-	dbx = get_cert_list(L"dbx", &secure_var, &dbxsize);
+	dbx = get_cert_list(L"dbx", &secure_var, &dbxsize, &status);
 	if (!dbx) {
-		pr_info("Couldn't get UEFI dbx list\n");
+		if (status == EFI_NOT_FOUND)
+			pr_debug("dbx variable wasn't found\n");
+		else
+			pr_info("Couldn't get UEFI dbx list\n");
 	} else {
 		rc = parse_efi_signature_list("UEFI:dbx",
 					      dbx, dbxsize,
@@ -119,6 +176,24 @@ static int __init load_uefi_certs(void)
 		kfree(dbx);
 	}
 
+	mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize, &status);
+	if (!mokx) {
+		if (status == EFI_NOT_FOUND)
+			pr_debug("mokx variable wasn't found\n");
+		else
+			pr_info("Couldn't get mokx list\n");
+	} else {
+		rc = parse_efi_signature_list("UEFI:MokListXRT",
+					      mokx, mokxsize,
+					      get_handler_for_dbx);
+		if (rc)
+			pr_err("Couldn't parse mokx signatures %d\n", rc);
+		kfree(mokx);
+	}
+
+	/* Load the MokListRT certs */
+	rc = load_moklist_certs();
+
 	return rc;
 }
 late_initcall(load_uefi_certs);