[PATCH 3/5] MODSIGN: load blacklist from MOKx

From: Lee, Chun-Yi
Date: Tue Mar 13 2018 - 06:39:24 EST


This patch adds the logic to load the blacklisted hash and
certificates from MOKx which is maintained by shim bootloader.

Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: "Lee, Chun-Yi" <jlee@xxxxxxxx>
---
certs/load_uefi.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/certs/load_uefi.c b/certs/load_uefi.c
index f2f372b..dc66a79 100644
--- a/certs/load_uefi.c
+++ b/certs/load_uefi.c
@@ -164,8 +164,8 @@ 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, *mok = NULL, *mokx = NULL;
+ unsigned long dbsize = 0, dbxsize = 0, moksize = 0, mokxsize = 0;
int rc = 0;

if (!efi.get_variable)
@@ -195,7 +195,7 @@ static int __init load_uefi_certs(void)
kfree(dbx);
}

- /* the MOK can not be trusted when secure boot is disabled */
+ /* the MOK and MOKx can not be trusted when secure boot is disabled */
if (!efi_enabled(EFI_SECURE_BOOT))
return 0;

@@ -208,6 +208,16 @@ static int __init load_uefi_certs(void)
kfree(mok);
}

+ mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize);
+ if (mokx) {
+ rc = parse_efi_signature_list("UEFI:mokx",
+ mokx, mokxsize,
+ get_handler_for_dbx);
+ if (rc)
+ pr_err("Couldn't parse MokListXRT signatures: %d\n", rc);
+ kfree(mokx);
+ }
+
return rc;
}
late_initcall(load_uefi_certs);
--
2.10.2