[PATCH v13 12/26] ima: Only accept AUDIT rules for non-init_ima_ns namespaces for now

From: Stefan Berger <stefanb@linux.ibm.com>
To: linux-integrity@vger.kernel.org
Cc: zohar@linux.ibm.com, serge@hallyn.com,
	christian.brauner@ubuntu.com, containers@lists.linux.dev,
	dmitry.kasatkin@gmail.com, ebiederm@xmission.com,
	krzysztof.struczynski@huawei.com, roberto.sassu@huawei.com,
	mpeters@redhat.com, lhinds@redhat.com, lsturman@redhat.com,
	puiterwi@redhat.com, jejb@linux.ibm.com, jamjoom@us.ibm.com,
	linux-kernel@vger.kernel.org, paul@paul-moore.com,
	rgb@redhat.com, linux-security-module@vger.kernel.org,
	jmorris@namei.org, jpenumak@redhat.com,
	Stefan Berger <stefanb@linux.ibm.com>,
	Christian Brauner <brauner@kernel.org>
Subject: [PATCH v13 12/26] ima: Only accept AUDIT rules for non-init_ima_ns namespaces for now
Date: Thu,  7 Jul 2022 10:47:46 -0400	[thread overview]
Message-ID: <20220707144800.828288-13-stefanb@linux.ibm.com> (raw)
In-Reply-To: <20220707144800.828288-1-stefanb@linux.ibm.com>

For non-init_ima_ns namespaces, only accept AUDIT rules for now. Reject
all rules that require support for measuring, appraisal, and hashing.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>

---
v9:
  - Jump to err_audit when unsupported rules are detected
---
 security/integrity/ima/ima_policy.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index de335dd97309..4a7e1e57655d 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -1865,6 +1865,17 @@ static int ima_parse_rule(struct ima_namespace *ns,
 			result = -EINVAL;
 			break;
 		}
+
+		/* IMA namespace only accepts AUDIT rules */
+		if (ns != &init_ima_ns && result == 0) {
+			switch (entry->action) {
+			case MEASURE:
+			case APPRAISE:
+			case HASH:
+				result = -EINVAL;
+				goto err_audit;
+			}
+		}
 	}
 	if (!result && !ima_validate_rule(entry))
 		result = -EINVAL;
@@ -1886,6 +1897,7 @@ static int ima_parse_rule(struct ima_namespace *ns,
 				     "verity rules should include d-ngv2");
 	}
 
+err_audit:
 	audit_log_format(ab, "res=%d", !result);
 	audit_log_end(ab);
 	return result;
-- 
2.36.1

