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,
        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,
        Stefan Berger <stefanb@linux.ibm.com>
Subject: [PATCH v8 07/19] ima: Move dentry into ima_namespace and others onto stack
Date:   Tue,  4 Jan 2022 12:04:04 -0500
Message-Id: <20220104170416.1923685-8-stefanb@linux.vnet.ibm.com>
In-Reply-To: <20220104170416.1923685-1-stefanb@linux.vnet.ibm.com>
References: <20220104170416.1923685-1-stefanb@linux.vnet.ibm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Stefan Berger <stefanb@linux.ibm.com>

Move the policy file dentry into the ima_namespace for reuse by
virtualized SecurityFS and for being able to remove it from
the filesystem. Move the other dentries onto the stack.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
 security/integrity/ima/ima.h    |  2 ++
 security/integrity/ima/ima_fs.c | 32 ++++++++++++++++++--------------
 2 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 82b3f6a98320..224b09617c52 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -140,6 +140,8 @@ struct ima_namespace {
 	struct mutex ima_write_mutex;
 	unsigned long ima_fs_flags;
 	int valid_policy;
+
+	struct dentry *policy_dentry;
 } __randomize_layout;
 extern struct ima_namespace init_ima_ns;
 
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 973bf17754b2..5b6404991b37 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -359,14 +359,6 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf,
 	return result;
 }
 
-static struct dentry *ima_dir;
-static struct dentry *ima_symlink;
-static struct dentry *binary_runtime_measurements;
-static struct dentry *ascii_runtime_measurements;
-static struct dentry *runtime_measurements_count;
-static struct dentry *violations;
-static struct dentry *ima_policy;
-
 enum ima_fs_flags {
 	IMA_FS_BUSY,
 };
@@ -436,8 +428,8 @@ static int ima_release_policy(struct inode *inode, struct file *file)
 
 	ima_update_policy(ns);
 #if !defined(CONFIG_IMA_WRITE_POLICY) && !defined(CONFIG_IMA_READ_POLICY)
-	securityfs_remove(ima_policy);
-	ima_policy = NULL;
+	securityfs_remove(ns->policy_dentry);
+	ns->policy_dentry = NULL;
 #elif defined(CONFIG_IMA_WRITE_POLICY)
 	clear_bit(IMA_FS_BUSY, &ns->ima_fs_flags);
 #elif defined(CONFIG_IMA_READ_POLICY)
@@ -454,8 +446,15 @@ static const struct file_operations ima_measure_policy_ops = {
 	.llseek = generic_file_llseek,
 };
 
-int __init ima_fs_init(void)
+static int __init ima_fs_ns_init(struct ima_namespace *ns)
 {
+	struct dentry *ima_dir;
+	struct dentry *ima_symlink = NULL;
+	struct dentry *binary_runtime_measurements = NULL;
+	struct dentry *ascii_runtime_measurements = NULL;
+	struct dentry *runtime_measurements_count = NULL;
+	struct dentry *violations = NULL;
+
 	ima_dir = securityfs_create_dir("ima", integrity_dir);
 	if (IS_ERR(ima_dir))
 		return -1;
@@ -492,20 +491,25 @@ int __init ima_fs_init(void)
 	if (IS_ERR(violations))
 		goto out;
 
-	ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS,
+	ns->policy_dentry = securityfs_create_file("policy", POLICY_FILE_FLAGS,
 					    ima_dir, NULL,
 					    &ima_measure_policy_ops);
-	if (IS_ERR(ima_policy))
+	if (IS_ERR(ns->policy_dentry))
 		goto out;
 
 	return 0;
 out:
+	securityfs_remove(ns->policy_dentry);
 	securityfs_remove(violations);
 	securityfs_remove(runtime_measurements_count);
 	securityfs_remove(ascii_runtime_measurements);
 	securityfs_remove(binary_runtime_measurements);
 	securityfs_remove(ima_symlink);
 	securityfs_remove(ima_dir);
-	securityfs_remove(ima_policy);
 	return -1;
 }
+
+int __init ima_fs_init(void)
+{
+	return ima_fs_ns_init(&init_ima_ns);
+}
-- 
2.31.1