[PATCH v5 05/16] ima: Move IMA's keys queue related variables into ima_namespace

Stefan Berger
2021-12-08T22:18:33Z

Move variables from keys queue into ima_namespace.

Some variables have to be initialized before ima_init() runs, so statically
initialize them for the init_ima_ns.

Since only init_ima_ns uses the queued keys there's no need to free the
list of queued keys when tearing down IMA namespaces.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
include/linux/ima.h | 11 ++++++
security/integrity/ima/ima.h | 9 ++---
security/integrity/ima/ima_asymmetric_keys.c | 5 +--
security/integrity/ima/ima_init_ima_ns.c | 5 +++
security/integrity/ima/ima_ns.c | 6 ++++
security/integrity/ima/ima_queue_keys.c | 37 +++++++-------------
6 files changed, 43 insertions(+), 30 deletions(-)

diff --git a/include/linux/ima.h b/include/linux/ima.h
index 529defe4d272..0ce58c17cb25 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -219,6 +219,17 @@ struct ima_namespace {
struct kmem_cache *ns_status_cache;

#ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS
+ /*
+ * Flag to indicate whether a key can be processed
+ * right away or should be queued for processing later.
+ */
+ bool ima_process_keys;
+
+ /*
+ * To synchronize access to the list of keys that need to be measured
+ */
+ struct mutex ima_keys_lock;
+ struct list_head ima_keys;
/*
* If custom IMA policy is not loaded then keys queued up
* for measurement should be freed. This worker is used
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 9edab9050dc7..97eb03376855 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -250,14 +250,15 @@ struct ima_key_entry {
char *keyring_name;
};
void ima_init_key_queue(struct ima_namespace *ns);
-bool ima_should_queue_key(void);
-bool ima_queue_key(struct key *keyring, const void *payload,
+bool ima_should_queue_key(struct ima_namespace *ns);
+bool ima_queue_key(struct ima_namespace *ns, struct key *keyring, const void *payload,
size_t payload_len);
void ima_process_queued_keys(struct ima_namespace *ns);
void ima_keys_handler(struct work_struct *work);
#else
-static inline bool ima_should_queue_key(void) { return false; }
-static inline bool ima_queue_key(struct key *keyring,
+static inline bool ima_should_queue_key(struct ima_namespace *ns) { return false; }
+static inline bool ima_queue_key(struct ima_namespace *ns,
+ struct key *keyring,
const void *payload,
size_t payload_len) { return false; }
static inline void ima_process_queued_keys(struct ima_namespace *ns) {}
diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c
index f6aa0b47a772..b20e82eda8f4 100644
--- a/security/integrity/ima/ima_asymmetric_keys.c
+++ b/security/integrity/ima/ima_asymmetric_keys.c
@@ -30,6 +30,7 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key,
const void *payload, size_t payload_len,
unsigned long flags, bool create)
{
+ struct ima_namespace *ns = get_current_ns();
bool queued = false;

/* Only asymmetric keys are handled by this hook. */
@@ -39,8 +40,8 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key,
if (!payload || (payload_len == 0))
return;

- if (ima_should_queue_key())
- queued = ima_queue_key(keyring, payload, payload_len);
+ if (ima_should_queue_key(ns))
+ queued = ima_queue_key(ns, keyring, payload, payload_len);

if (queued)
return;
diff --git a/security/integrity/ima/ima_init_ima_ns.c b/security/integrity/ima/ima_init_ima_ns.c
index 75ef17d52b5b..144b30ceefb0 100644
--- a/security/integrity/ima/ima_init_ima_ns.c
+++ b/security/integrity/ima/ima_init_ima_ns.c
@@ -45,5 +45,10 @@ int __init ima_ns_init(void)
struct ima_namespace init_ima_ns = {
.kref = KREF_INIT(1),
.user_ns = &init_user_ns,
+#ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS
+ .ima_process_keys = false,
+ .ima_keys_lock = __MUTEX_INITIALIZER(init_ima_ns.ima_keys_lock),
+ .ima_keys = LIST_HEAD_INIT(init_ima_ns.ima_keys),
+#endif
};
EXPORT_SYMBOL(init_ima_ns);
diff --git a/security/integrity/ima/ima_ns.c b/security/integrity/ima/ima_ns.c
index 000dbde2f264..1ee724bab714 100644
--- a/security/integrity/ima/ima_ns.c
+++ b/security/integrity/ima/ima_ns.c
@@ -38,6 +38,12 @@ int create_ima_ns(struct user_namespace *user_ns)
if (err)
goto fail_free;

+#ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS
+ ns->ima_process_keys = false;
+ mutex_init(&ns->ima_keys_lock);
+ INIT_LIST_HEAD(&ns->ima_keys);
+#endif
+
user_ns->ima_ns = ns;

return 0;
diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c
index ed5923dfe71b..4c69178b1ffe 100644
--- a/security/integrity/ima/ima_queue_keys.c
+++ b/security/integrity/ima/ima_queue_keys.c
@@ -14,17 +14,6 @@
#include <keys/asymmetric-type.h>
#include "ima.h"

-/*
- * Flag to indicate whether a key can be processed
- * right away or should be queued for processing later.
- */
-static bool ima_process_keys;
-
-/*
- * To synchronize access to the list of keys that need to be measured
- */
-static DEFINE_MUTEX(ima_keys_lock);
-static LIST_HEAD(ima_keys);

/*
* This worker function frees keys that may still be
@@ -100,7 +89,7 @@ static struct ima_key_entry *ima_alloc_key_entry(struct key *keyring,
return entry;
}

-bool ima_queue_key(struct key *keyring, const void *payload,
+bool ima_queue_key(struct ima_namespace *ns, struct key *keyring, const void *payload,
size_t payload_len)
{
bool queued = false;
@@ -110,12 +99,12 @@ bool ima_queue_key(struct key *keyring, const void *payload,
if (!entry)
return false;

- mutex_lock(&ima_keys_lock);
- if (!ima_process_keys) {
- list_add_tail(&entry->list, &ima_keys);
+ mutex_lock(&ns->ima_keys_lock);
+ if (!ns->ima_process_keys) {
+ list_add_tail(&entry->list, &ns->ima_keys);
queued = true;
}
- mutex_unlock(&ima_keys_lock);
+ mutex_unlock(&ns->ima_keys_lock);

if (!queued)
ima_free_key_entry(entry);
@@ -134,7 +123,7 @@ void ima_process_queued_keys(struct ima_namespace *ns)
struct ima_key_entry *entry, *tmp;
bool process = false;

- if (ima_process_keys)
+ if (ns->ima_process_keys)
return;

/*
@@ -143,12 +132,12 @@ void ima_process_queued_keys(struct ima_namespace *ns)
* First one setting the ima_process_keys flag to true will
* process the queued keys.
*/
- mutex_lock(&ima_keys_lock);
- if (!ima_process_keys) {
- ima_process_keys = true;
+ mutex_lock(&ns->ima_keys_lock);
+ if (!ns->ima_process_keys) {
+ ns->ima_process_keys = true;
process = true;
}
- mutex_unlock(&ima_keys_lock);
+ mutex_unlock(&ns->ima_keys_lock);

if (!process)
return;
@@ -159,7 +148,7 @@ void ima_process_queued_keys(struct ima_namespace *ns)
put_user_ns(ns->user_ns);
}

- list_for_each_entry_safe(entry, tmp, &ima_keys, list) {
+ list_for_each_entry_safe(entry, tmp, &ns->ima_keys, list) {
if (!ns->timer_expired)
process_buffer_measurement(&init_user_ns, NULL,
entry->payload,
@@ -173,7 +162,7 @@ void ima_process_queued_keys(struct ima_namespace *ns)
}
}

-inline bool ima_should_queue_key(void)
+inline bool ima_should_queue_key(struct ima_namespace *ns)
{
- return !ima_process_keys;
+ return !ns->ima_process_keys;
}
--
2.31.1