[PATCH v2 09/11] ima: Move validation of the keyrings conditional into ima_validate_rule()

[Tyler Hicks]

Use ima_validate_rule() to ensure that the combination of a hook
function and the keyrings conditional is valid and that the keyrings
conditional is not specified without an explicit KEY_CHECK func
conditional. This is a code cleanup and has no user-facing change.

Signed-off-by: Tyler Hicks <tyhicks at linux.microsoft.com>
---

* v2
  - Allowed IMA_DIGSIG_REQUIRED, IMA_PERMIT_DIRECTIO,
    IMA_MODSIG_ALLOWED, and IMA_CHECK_BLACKLIST conditionals to be
    present in the rule entry flags for non-buffer hook functions.

 security/integrity/ima/ima_policy.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 8cdca2399d59..43d49ad958fb 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -1000,6 +1000,15 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
 		case KEXEC_KERNEL_CHECK:
 		case KEXEC_INITRAMFS_CHECK:
 		case POLICY_CHECK:
+			if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC |
+					     IMA_UID | IMA_FOWNER | IMA_FSUUID |
+					     IMA_INMASK | IMA_EUID | IMA_PCR |
+					     IMA_FSNAME | IMA_DIGSIG_REQUIRED |
+					     IMA_PERMIT_DIRECTIO |
+					     IMA_MODSIG_ALLOWED |
+					     IMA_CHECK_BLACKLIST))
+				return false;
+
 			break;
 		case KEXEC_CMDLINE:
 			if (entry->action & ~(MEASURE | DONT_MEASURE))
@@ -1027,7 +1036,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
 		default:
 			return false;
 		}
-	}
+	} else if (entry->flags & IMA_KEYRINGS)
+		return false;
 
 	return true;
 }
@@ -1209,7 +1219,6 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 			keyrings_len = strlen(args[0].from) + 1;
 
 			if ((entry->keyrings) ||
-			    (entry->func != KEY_CHECK) ||
 			    (keyrings_len < 2)) {
 				result = -EINVAL;
 				break;
-- 
2.25.1