[PATCH] ima: require signed IMA policy when UEFI secure boot is enabled

[Coiby Xu <coxu@redhat.com>]

With the introduction of the .machine keyring for UEFI-based systems,
users are able to add custom CAs keys via MOK. This allow users to sign
their own IMA polices. For the sake of security, mandate signed IMA
policy when UEFI secure boot is enabled.

Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 security/integrity/ima/ima_efi.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/security/integrity/ima/ima_efi.c b/security/integrity/ima/ima_efi.c
index 9db66fe310d4..bb2881759505 100644
--- a/security/integrity/ima/ima_efi.c
+++ b/security/integrity/ima/ima_efi.c
@@ -58,6 +58,9 @@ static const char * const sb_arch_rules[] = {
 #if !IS_ENABLED(CONFIG_MODULE_SIG)
 	"appraise func=MODULE_CHECK appraise_type=imasig",
 #endif
+#if IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING) && IS_ENABLED(CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY)
+	"appraise func=POLICY_CHECK appraise_type=imasig",
+#endif /* CONFIG_INTEGRITY_MACHINE_KEYRING && IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY */
 	"measure func=MODULE_CHECK",
 	NULL
 };
-- 
2.41.0