[PATCH] selinux: add hooks for key subsystem

Introduce SELinux hooks to support the access key retention subsystem
within the kernel.  Incorporate new flask headers from a modified version
of the SELinux reference policy, with support for the new security class
representing retained keys.  Extend the "key_alloc" security hook with a
task parameter representing the intended ownership context for the key
being allocated.  Attach security information to root's default keyrings
within the SELinux initialization routine.

Has passed David's testsuite.

Signed-off-by: Michael LeMay <mdlemay@epoch.ncsc.mil>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 19 insertions, 9 deletions

diff --git a/include/linux/key.h b/include/linux/key.h
index cbf464a..8c275d1 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -241,8 +241,9 @@ extern void unregister_key_type(struct key_type *ktype);
 
 extern struct key *key_alloc(struct key_type *type,
 			     const char *desc,
-			     uid_t uid, gid_t gid, key_perm_t perm,
-			     int not_in_quota);
+			     uid_t uid, gid_t gid,
+			     struct task_struct *ctx,
+			     key_perm_t perm, int not_in_quota);
 extern int key_payload_reserve(struct key *key, size_t datalen);
 extern int key_instantiate_and_link(struct key *key,
 				    const void *data,
@@ -292,7 +293,9 @@ extern int key_unlink(struct key *keyring,
 		      struct key *key);
 
 extern struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
-				 int not_in_quota, struct key *dest);
+				 struct task_struct *ctx,
+				 int not_in_quota,
+				 struct key *dest);
 
 extern int keyring_clear(struct key *keyring);
 
@@ -313,7 +316,8 @@ extern void keyring_replace_payload(struct key *key, void *replacement);
  * the userspace interface
  */
 extern struct key root_user_keyring, root_session_keyring;
-extern int alloc_uid_keyring(struct user_struct *user);
+extern int alloc_uid_keyring(struct user_struct *user,
+			     struct task_struct *ctx);
 extern void switch_uid_keyring(struct user_struct *new_user);
 extern int copy_keys(unsigned long clone_flags, struct task_struct *tsk);
 extern int copy_thread_group_keys(struct task_struct *tsk);
@@ -342,7 +346,7 @@ extern void key_init(void);
 #define make_key_ref(k)			({ NULL; })
 #define key_ref_to_ptr(k)		({ NULL; })
 #define is_key_possessed(k)		0
-#define alloc_uid_keyring(u)		0
+#define alloc_uid_keyring(u,c)		0
 #define switch_uid_keyring(u)		do { } while(0)
 #define __install_session_keyring(t, k)	({ NULL; })
 #define copy_keys(f,t)			0
@@ -355,6 +359,10 @@ extern void key_init(void);
 #define key_fsgid_changed(t)		do { } while(0)
 #define key_init()			do { } while(0)
 
+/* Initial keyrings */
+extern struct key root_user_keyring;
+extern struct key root_session_keyring;
+
 #endif /* CONFIG_KEYS */
 #endif /* __KERNEL__ */
 #endif /* _LINUX_KEY_H */
diff --git a/include/linux/security.h b/include/linux/security.h
index 4dfb1b8..47722d3 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1313,7 +1313,7 @@ struct security_operations {
 
 	/* key management security hooks */
 #ifdef CONFIG_KEYS
-	int (*key_alloc)(struct key *key);
+	int (*key_alloc)(struct key *key, struct task_struct *tsk);
 	void (*key_free)(struct key *key);
 	int (*key_permission)(key_ref_t key_ref,
 			      struct task_struct *context,
@@ -3008,9 +3008,10 @@ static inline int security_xfrm_policy_lookup(struct xfrm_policy *xp, u32 sk_sid
 
 #ifdef CONFIG_KEYS
 #ifdef CONFIG_SECURITY
-static inline int security_key_alloc(struct key *key)
+static inline int security_key_alloc(struct key *key,
+				     struct task_struct *tsk)
 {
-	return security_ops->key_alloc(key);
+	return security_ops->key_alloc(key, tsk);
 }
 
 static inline void security_key_free(struct key *key)
@@ -3027,7 +3028,8 @@ static inline int security_key_permission(key_ref_t key_ref,
 
 #else
 
-static inline int security_key_alloc(struct key *key)
+static inline int security_key_alloc(struct key *key,
+				     struct task_struct *tsk)
 {
 	return 0;
 }