From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <[email protected]>
Date: Wed, 24 Feb 2021 14:44:38 +0100
Subject: [PATCH] loader/xnu: Don't allow loading extension and packages when
 locked down

The shim_lock verifier validates the XNU kernels but no its extensions
and packages. Prevent these to be loaded when the GRUB is locked down.

Signed-off-by: Javier Martinez Canillas <[email protected]>
Reviewed-by: Daniel Kiper <[email protected]>
---
 grub-core/loader/xnu.c | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/grub-core/loader/xnu.c b/grub-core/loader/xnu.c
index 5944dc5ea..b33a38432 100644
--- a/grub-core/loader/xnu.c
+++ b/grub-core/loader/xnu.c
@@ -1489,20 +1489,23 @@ GRUB_MOD_INIT(xnu)
 				      N_("Load XNU image."));
   cmd_kernel64 = grub_register_command ("xnu_kernel64", grub_cmd_xnu_kernel64,
 					0, N_("Load 64-bit XNU image."));
-  cmd_mkext = grub_register_command ("xnu_mkext", grub_cmd_xnu_mkext, 0,
-				     N_("Load XNU extension package."));
-  cmd_kext = grub_register_command ("xnu_kext", grub_cmd_xnu_kext, 0,
-				    N_("Load XNU extension."));
-  cmd_kextdir = grub_register_command ("xnu_kextdir", grub_cmd_xnu_kextdir,
-				       /* TRANSLATORS: OSBundleRequired is a
-					  variable name in xnu extensions
-					  manifests. It behaves mostly like
-					  GNU/Linux runlevels.
-				       */
-				       N_("DIRECTORY [OSBundleRequired]"),
-				       /* TRANSLATORS: There are many extensions
-					  in extension directory.  */
-				       N_("Load XNU extension directory."));
+  cmd_mkext = grub_register_command_lockdown ("xnu_mkext", grub_cmd_xnu_mkext, 0,
+					      N_("Load XNU extension package."));
+  cmd_kext = grub_register_command_lockdown ("xnu_kext", grub_cmd_xnu_kext, 0,
+					     N_("Load XNU extension."));
+  cmd_kextdir = grub_register_command_lockdown ("xnu_kextdir", grub_cmd_xnu_kextdir,
+						/*
+						 * TRANSLATORS: OSBundleRequired is
+						 * a variable name in xnu extensions
+						 * manifests. It behaves mostly like
+						 * GNU/Linux runlevels.
+						 */
+						N_("DIRECTORY [OSBundleRequired]"),
+						/*
+						 * TRANSLATORS: There are many extensions
+						 * in extension directory.
+						 */
+						N_("Load XNU extension directory."));
   cmd_ramdisk = grub_register_command ("xnu_ramdisk", grub_cmd_xnu_ramdisk, 0,
    /* TRANSLATORS: ramdisk here isn't identifier. It can be translated.  */
 				       N_("Load XNU ramdisk. "