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From:   Stefan Berger <stefanb@linux.vnet.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,
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        linux-kernel@vger.kernel.org, paul@paul-moore.com, rgb@redhat.com,
        linux-security-module@vger.kernel.org, jmorris@namei.org,
        Stefan Berger <stefanb@linux.ibm.com>
Subject: [PATCH v9 13/23] ima: Only accept AUDIT rules for non-init_ima_ns namespaces for now
Date:   Tue, 25 Jan 2022 17:46:35 -0500
Message-Id: <20220125224645.79319-14-stefanb@linux.vnet.ibm.com>
In-Reply-To: <20220125224645.79319-1-stefanb@linux.vnet.ibm.com>
References: <20220125224645.79319-1-stefanb@linux.vnet.ibm.com>
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From: Stefan Berger <stefanb@linux.ibm.com>

Only accept AUDIT rules for non-init_ima_ns namespaces rejecting all rules
that require support for measuring, appraisal, and hashing.

Signed-off-by: Stefan Berger <stefanb@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 3b754b9f5ef7..e8140e73d80b 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -1794,6 +1794,17 @@ 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;
@@ -1806,6 +1817,7 @@ static int ima_parse_rule(struct ima_namespace *ns,
 		check_template_modsig(template_desc);
 	}
 
+err_audit:
 	audit_log_format(ab, "res=%d", !result);
 	audit_log_end(ab);
 	return result;
-- 
2.31.1