[SRU][F/hwe-5.8][PATCH 06/18] integrity: Move import of MokListRT certs to a separate routine

[Dimitri John Ledkov]

From: Lenny Szubowicz <lszubowi at redhat.com>

BugLink: https://bugs.launchpad.net/bugs/1932029

Move the loading of certs from the UEFI MokListRT into a separate
routine to facilitate additional MokList functionality.

There is no visible functional change as a result of this patch.
Although the UEFI dbx certs are now loaded before the MokList certs,
they are loaded onto different key rings. So the order of the keys
on their respective key rings is the same.

Signed-off-by: Lenny Szubowicz <lszubowi at redhat.com>
Reviewed-by: Mimi Zohar <zohar at linux.ibm.com>
Link: https://lore.kernel.org/r/20200905013107.10457-3-lszubowi@redhat.com
Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
(cherry picked from commit 38a1f03aa24094b4a8de846700cb6cb21cc06468)
Signed-off-by: Dimitri John Ledkov <dimitri.ledkov at canonical.com>
---
 security/integrity/platform_certs/load_uefi.c | 63 +++++++++++++------
 1 file changed, 44 insertions(+), 19 deletions(-)

diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index 8c95b68d86..fd03a47272 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -68,6 +68,43 @@ 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.
+ *
+ * Return:	Status
+ */
+static int __init load_moklist_certs(void)
+{
+	efi_guid_t mok_var = EFI_SHIM_LOCK_GUID;
+	void *mok;
+	unsigned long moksize;
+	efi_status_t status;
+	int 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.
@@ -75,17 +112,16 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
 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;
+	unsigned long dbsize = 0, dbxsize = 0;
 	efi_status_t status;
 	int rc = 0;
 
 	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, &status);
@@ -104,20 +140,6 @@ static int __init load_uefi_certs(void)
 		}
 	}
 
-	mok = get_cert_list(L"MokListRT", &mok_var, &moksize, &status);
-	if (!mok) {
-		if (status == EFI_NOT_FOUND)
-			pr_debug("MokListRT variable wasn't found\n");
-		else
-			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, &status);
 	if (!dbx) {
 		if (status == EFI_NOT_FOUND)
@@ -133,6 +155,9 @@ static int __init load_uefi_certs(void)
 		kfree(dbx);
 	}
 
+	/* Load the MokListRT certs */
+	rc = load_moklist_certs();
+
 	return rc;
 }
 late_initcall(load_uefi_certs);
-- 
2.30.2