[PATCH 22/28] security: Introduce key_post_create_or_update hook

[Roberto Sassu]

From: Roberto Sassu <roberto.sassu at huawei.com>

In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the key_post_create_or_update hook.

Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>
---
 include/linux/lsm_hook_defs.h |  3 +++
 include/linux/security.h      | 11 +++++++++++
 security/keys/key.c           |  7 ++++++-
 security/security.c           | 19 +++++++++++++++++++
 4 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 6c324fe5099..cf171e65420 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -397,6 +397,9 @@ LSM_HOOK(void, LSM_RET_VOID, key_free, struct key *key)
 LSM_HOOK(int, 0, key_permission, key_ref_t key_ref, const struct cred *cred,
 	 enum key_need_perm need_perm)
 LSM_HOOK(int, 0, key_getsecurity, struct key *key, char **_buffer)
+LSM_HOOK(void, LSM_RET_VOID, key_post_create_or_update, struct key *keyring,
+	 struct key *key, const void *payload, size_t payload_len,
+	 unsigned long flags, bool create)
 #endif /* CONFIG_KEYS */
 
 #ifdef CONFIG_AUDIT
diff --git a/include/linux/security.h b/include/linux/security.h
index f8df5b69667..be23a303bba 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1952,6 +1952,9 @@ void security_key_free(struct key *key);
 int security_key_permission(key_ref_t key_ref, const struct cred *cred,
 			    enum key_need_perm need_perm);
 int security_key_getsecurity(struct key *key, char **_buffer);
+void security_key_post_create_or_update(struct key *keyring, struct key *key,
+					const void *payload, size_t payload_len,
+					unsigned long flags, bool create);
 
 #else
 
@@ -1979,6 +1982,14 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
 	return 0;
 }
 
+static inline void security_key_post_create_or_update(struct key *keyring,
+						      struct key *key,
+						      const void *payload,
+						      size_t payload_len,
+						      unsigned long flags,
+						      bool create)
+{ }
+
 #endif
 #endif /* CONFIG_KEYS */
 
diff --git a/security/keys/key.c b/security/keys/key.c
index 5c0c7df833f..0f9c6faf349 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -934,6 +934,8 @@ static key_ref_t __key_create_or_update(key_ref_t keyring_ref,
 		goto error_link_end;
 	}
 
+	security_key_post_create_or_update(keyring, key, payload, plen, flags,
+					   true);
 	ima_post_key_create_or_update(keyring, key, payload, plen,
 				      flags, true);
 
@@ -967,10 +969,13 @@ static key_ref_t __key_create_or_update(key_ref_t keyring_ref,
 
 	key_ref = __key_update(key_ref, &prep);
 
-	if (!IS_ERR(key_ref))
+	if (!IS_ERR(key_ref)) {
+		security_key_post_create_or_update(keyring, key, payload, plen,
+						   flags, false);
 		ima_post_key_create_or_update(keyring, key,
 					      payload, plen,
 					      flags, false);
+	}
 
 	goto error_free_prep;
 }
diff --git a/security/security.c b/security/security.c
index b3a9c317f75..322090a50cd 100644
--- a/security/security.c
+++ b/security/security.c
@@ -5195,6 +5195,25 @@ int security_key_getsecurity(struct key *key, char **_buffer)
 	*_buffer = NULL;
 	return call_int_hook(key_getsecurity, 0, key, _buffer);
 }
+
+/**
+ * security_key_post_create_or_update() - Tell caller of key creation or update
+ * @keyring: keyring to which the key is linked to
+ * @key: created or updated key
+ * @payload: data used to instantiate or update the key
+ * @payload_len: length of payload
+ * @flags: key flags
+ * @create: flag indicating whether the key was created or updated
+ *
+ * Notify the caller of a key creation or update.
+ */
+void security_key_post_create_or_update(struct key *keyring, struct key *key,
+					const void *payload, size_t payload_len,
+					unsigned long flags, bool create)
+{
+	call_void_hook(key_post_create_or_update, keyring, key, payload,
+		       payload_len, flags, create);
+}
 #endif	/* CONFIG_KEYS */
 
 #ifdef CONFIG_AUDIT
-- 
2.25.1