integrity: Load mokx variables into the blacklist keyring

ebd9c2ae · Eric Snowberg <[email protected]> · 2021-01-22 13:10:54 -05:00

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 <[email protected]>
Suggested-by: James Bottomley <[email protected]>
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
cc: [email protected]
Link: https://lore.kernel.org/r/c33c8e3839a41e9654f41cc92c7231104931b1d7.camel@HansenPartnership.com/
Link: https://lore.kernel.org/r/[email protected]/ # 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

Commit: ebd9c2ae369a45bdd9f8615484db09be58fc242b
Parents: d1f04410

Changes

1 files changed · +18 −2

File	Status	Add	Del	Content
security/integrity/platform_certs/load_uefi.c	modified	+18	−2	View file

security/integrity/platform_certs/load_uefi.c

View file

diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index ee4b4c6..f290f78 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -132,8 +132,9 @@ 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;
 
@@ -175,6 +176,21 @@ 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();
 