[FOCAL][linux-oem-5.10][PATCH 05/10] integrity: Load mokx variables into the blacklist keyring

[Dimitri John Ledkov]

From: Eric Snowberg <eric.snowberg at oracle.com>

[ Upstream commit ebd9c2ae369a45bdd9f8615484db09be58fc242b ]

During boot the Secure Boot Forbidden Signature Database, dbx,
is loaded into the blacklist keyring.  Systems booted with shim
have an equivalent Forbidden Signature Database called mokx.
Currently mokx is only used by shim and grub, the contents are
ignored by the kernel.

Add the ability to load mokx into the blacklist keyring during boot.

Signed-off-by: Eric Snowberg <eric.snowberg at oracle.com>
Suggested-by: James Bottomley <James.Bottomley at HansenPartnership.com>
Signed-off-by: David Howells <dhowells at redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko at kernel.org>
cc: keyrings at vger.kernel.org
Link: https://lore.kernel.org/r/c33c8e3839a41e9654f41cc92c7231104931b1d7.camel@HansenPartnership.com/
Link: https://lore.kernel.org/r/20210122181054.32635-5-eric.snowberg@oracle.com/ # v5
Link: https://lore.kernel.org/r/161428674320.677100.12637282414018170743.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/161433313205.902181.2502803393898221637.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161529607422.163428.13530426573612578854.stgit@warthog.procyon.org.uk/ # v3
Signed-off-by: Sasha Levin <sashal at kernel.org>
(cherry picked from commit 1573d595e2395c4d2742d2217d86f6241ca47b9f)
---
 security/integrity/platform_certs/load_uefi.c | 20 +++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index eff9ff5934..d3e7ae04f5 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -134,8 +134,9 @@ static int __init load_moklist_certs(void)
 static int __init load_uefi_certs(void)
 {
 	efi_guid_t secure_var = EFI_IMAGE_SECURITY_DATABASE_GUID;
-	void *db = NULL, *dbx = NULL;
-	unsigned long dbsize = 0, dbxsize = 0;
+	efi_guid_t mok_var = EFI_SHIM_LOCK_GUID;
+	void *db = NULL, *dbx = NULL, *mokx = NULL;
+	unsigned long dbsize = 0, dbxsize = 0, mokxsize = 0;
 	efi_status_t status;
 	int rc = 0;
 
@@ -177,6 +178,21 @@ 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();
 
-- 
2.30.2