diff mbox series

[v9,09/23] ima: Move some IMA policy and filesystem related variables into ima_namespace

Message ID 20220125224645.79319-10-stefanb@linux.vnet.ibm.com (mailing list archive)
State New, archived
Headers show
Series ima: Namespace IMA with audit support in IMA-ns | expand

Commit Message

Stefan Berger Jan. 25, 2022, 10:46 p.m. UTC 
From: Stefan Berger <stefanb@linux.ibm.com>

Move the ima_write_mutex, ima_fs_flag, and valid_policy variables into
ima_namespace. This way each IMA namespace can set those variables
independently.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
 security/integrity/ima/ima.h             |  5 ++++
 security/integrity/ima/ima_fs.c          | 32 +++++++++++-------------
 security/integrity/ima/ima_init_ima_ns.c |  4 +++
 3 files changed, 23 insertions(+), 18 deletions(-)

Comments

Christian Brauner Jan. 26, 2022, 9:23 a.m. UTC | #1 
On Tue, Jan 25, 2022 at 05:46:31PM -0500, Stefan Berger wrote:
> From: Stefan Berger <stefanb@linux.ibm.com>
> 
> Move the ima_write_mutex, ima_fs_flag, and valid_policy variables into
> ima_namespace. This way each IMA namespace can set those variables
> independently.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> ---

Moving into imans looks good,
Acked-by: Christian Brauner <brauner@kernel.org>
Mimi Zohar Jan. 27, 2022, 10:30 p.m. UTC | #2 
On Tue, 2022-01-25 at 17:46 -0500, Stefan Berger wrote:
> From: Stefan Berger <stefanb@linux.ibm.com>
> 
> Move the ima_write_mutex, ima_fs_flag, and valid_policy variables into
> ima_namespace. This way each IMA namespace can set those variables
> independently.

This patch description needs to be expanded a bit, indicating why
they're being moved together.  These flags are needed when loading a
policy. Please also update the "struct ima_namespace" comment.

thanks,

Mimi
Stefan Berger Jan. 28, 2022, 3:44 p.m. UTC | #3 
On 1/27/22 17:30, Mimi Zohar wrote:
> On Tue, 2022-01-25 at 17:46 -0500, Stefan Berger wrote:
>> From: Stefan Berger <stefanb@linux.ibm.com>
>>
>> Move the ima_write_mutex, ima_fs_flag, and valid_policy variables into
>> ima_namespace. This way each IMA namespace can set those variables
>> independently.
> This patch description needs to be expanded a bit, indicating why
> they're being moved together.  These flags are needed when loading a
> policy. Please also update the "struct ima_namespace" comment.

I'll extend the above sentence like this:

... those variables independently in its instance of securityfs.

    Stefan

>
> thanks,
>
> Mimi
>
Mimi Zohar Jan. 28, 2022, 4:03 p.m. UTC | #4 
On Fri, 2022-01-28 at 10:44 -0500, Stefan Berger wrote:
> On 1/27/22 17:30, Mimi Zohar wrote:
> > On Tue, 2022-01-25 at 17:46 -0500, Stefan Berger wrote:
> >> From: Stefan Berger <stefanb@linux.ibm.com>
> >>
> >> Move the ima_write_mutex, ima_fs_flag, and valid_policy variables into
> >> ima_namespace. This way each IMA namespace can set those variables
> >> independently.
> > This patch description needs to be expanded a bit, indicating why
> > they're being moved together.  These flags are needed when loading a
> > policy. Please also update the "struct ima_namespace" comment.
> 
> I'll extend the above sentence like this:
> 
> ... those variables independently in its instance of securityfs.

That doesn't explain anything as to what these flags are or how they're
used.  Perhaps something like,  "Move the variables - ima_write_mutex,
ima_fs_flag, and valid_policy - related to updating the IMA policy into
the ima_namespace.  This way each IMA namespace can set these variables
independently."

Did you notice my comment inline below?

thanks,

Mimi
diff mbox series

Patch

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 45706836a77b..1092c926daf9 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -137,6 +137,11 @@  struct ima_namespace {
 	struct ima_h_table ima_htable;
 	struct list_head ima_measurements;	/* list of all measurements */
 	unsigned long binary_runtime_size;	/* used by init_ima_ns */
+
+	/* securityfs support related variables */
+	struct mutex ima_write_mutex;
+	unsigned long ima_fs_flags;
+	int valid_policy;
 } __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 b2f088dd8572..34132cc7de4d 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -24,8 +24,6 @@ 
 
 #include "ima.h"
 
-static DEFINE_MUTEX(ima_write_mutex);
-
 bool ima_canonical_fmt;
 static int __init default_canonical_fmt_setup(char *str)
 {
@@ -36,8 +34,6 @@  static int __init default_canonical_fmt_setup(char *str)
 }
 __setup("ima_canonical_fmt", default_canonical_fmt_setup);
 
-static int valid_policy = 1;
-
 static ssize_t ima_show_htable_value(char __user *buf, size_t count,
 				     loff_t *ppos, atomic_long_t *val)
 {
@@ -338,7 +334,7 @@  static ssize_t ima_write_policy(struct file *file, const char __user *buf,
 		goto out;
 	}
 
-	result = mutex_lock_interruptible(&ima_write_mutex);
+	result = mutex_lock_interruptible(&ns->ima_write_mutex);
 	if (result < 0)
 		goto out_free;
 
@@ -353,12 +349,12 @@  static ssize_t ima_write_policy(struct file *file, const char __user *buf,
 	} else {
 		result = ima_parse_add_rule(ns, data);
 	}
-	mutex_unlock(&ima_write_mutex);
+	mutex_unlock(&ns->ima_write_mutex);
 out_free:
 	kfree(data);
 out:
 	if (result < 0)
-		valid_policy = 0;
+		ns->valid_policy = 0;
 
 	return result;
 }
@@ -375,8 +371,6 @@  enum ima_fs_flags {
 	IMA_FS_BUSY,
 };
 
-static unsigned long ima_fs_flags;
-
 #ifdef	CONFIG_IMA_READ_POLICY
 static const struct seq_operations ima_policy_seqops = {
 		.start = ima_policy_start,
@@ -391,6 +385,8 @@  static const struct seq_operations ima_policy_seqops = {
  */
 static int ima_open_policy(struct inode *inode, struct file *filp)
 {
+	struct ima_namespace *ns = &init_ima_ns;
+
 	if (!(filp->f_flags & O_WRONLY)) {
 #ifndef	CONFIG_IMA_READ_POLICY
 		return -EACCES;
@@ -402,7 +398,7 @@  static int ima_open_policy(struct inode *inode, struct file *filp)
 		return seq_open(filp, &ima_policy_seqops);
 #endif
 	}
-	if (test_and_set_bit(IMA_FS_BUSY, &ima_fs_flags))
+	if (test_and_set_bit(IMA_FS_BUSY, &ns->ima_fs_flags))
 		return -EBUSY;
 	return 0;
 }
@@ -416,25 +412,25 @@  static int ima_open_policy(struct inode *inode, struct file *filp)
  */
 static int ima_release_policy(struct inode *inode, struct file *file)
 {
-	const char *cause = valid_policy ? "completed" : "failed";
 	struct ima_namespace *ns = &init_ima_ns;
+	const char *cause = ns->valid_policy ? "completed" : "failed";
 
 	if ((file->f_flags & O_ACCMODE) == O_RDONLY)
 		return seq_release(inode, file);
 
-	if (valid_policy && ima_check_policy(ns) < 0) {
+	if (ns->valid_policy && ima_check_policy(ns) < 0) {
 		cause = "failed";
-		valid_policy = 0;
+		ns->valid_policy = 0;
 	}
 
 	pr_info("policy update %s\n", cause);
 	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
-			    "policy_update", cause, !valid_policy, 0);
+			    "policy_update", cause, !ns->valid_policy, 0);
 
-	if (!valid_policy) {
+	if (!ns->valid_policy) {
 		ima_delete_rules(ns);
-		valid_policy = 1;
-		clear_bit(IMA_FS_BUSY, &ima_fs_flags);
+		ns->valid_policy = 1;
+		clear_bit(IMA_FS_BUSY, &ns->ima_fs_flags);
 		return 0;
 	}
 
@@ -443,7 +439,7 @@  static int ima_release_policy(struct inode *inode, struct file *file)
 	securityfs_remove(ima_policy);
 	ima_policy = NULL;
 #elif defined(CONFIG_IMA_WRITE_POLICY)
-	clear_bit(IMA_FS_BUSY, &ima_fs_flags);
+	clear_bit(IMA_FS_BUSY, &ns->ima_fs_flags);
 #elif defined(CONFIG_IMA_READ_POLICY)
 	inode->i_mode &= ~S_IWUSR;
 #endif
diff --git a/security/integrity/ima/ima_init_ima_ns.c b/security/integrity/ima/ima_init_ima_ns.c
index a7477072c587..425eed1c6838 100644
--- a/security/integrity/ima/ima_init_ima_ns.c
+++ b/security/integrity/ima/ima_init_ima_ns.c
@@ -26,6 +26,10 @@  static int ima_init_namespace(struct ima_namespace *ns)
 	else
 		ns->binary_runtime_size = ULONG_MAX;
 
+	mutex_init(&ns->ima_write_mutex);
+	ns->valid_policy = 1;
+	ns->ima_fs_flags = 0;
+
 	return 0;
 }