[PATCH] keys: sort out key quota system

Add the ability for key creation to overrun the user's quota in some
circumstances - notably when a session keyring is created and assigned to a
process that didn't previously have one.

This means it's still possible to log in, should PAM require the creation of a
new session keyring, and fix an overburdened key quota.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 17 insertions, 7 deletions

diff --git a/include/linux/key.h b/include/linux/key.h
index e81ebf9..e693e72 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -248,7 +248,14 @@ extern struct key *key_alloc(struct key_type *type,
 			     const char *desc,
 			     uid_t uid, gid_t gid,
 			     struct task_struct *ctx,
-			     key_perm_t perm, int not_in_quota);
+			     key_perm_t perm,
+			     unsigned long flags);
+
+
+#define KEY_ALLOC_IN_QUOTA	0x0000	/* add to quota, reject if would overrun */
+#define KEY_ALLOC_QUOTA_OVERRUN	0x0001	/* add to quota, permit even if overrun */
+#define KEY_ALLOC_NOT_IN_QUOTA	0x0002	/* 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,
@@ -285,7 +292,7 @@ extern key_ref_t key_create_or_update(key_ref_t keyring,
 				      const char *description,
 				      const void *payload,
 				      size_t plen,
-				      int not_in_quota);
+				      unsigned long flags);
 
 extern int key_update(key_ref_t key,
 		      const void *payload,
@@ -299,7 +306,7 @@ extern int key_unlink(struct key *keyring,
 
 extern struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
 				 struct task_struct *ctx,
-				 int not_in_quota,
+				 unsigned long flags,
 				 struct key *dest);
 
 extern int keyring_clear(struct key *keyring);
diff --git a/include/linux/security.h b/include/linux/security.h
index d2c17bd..5180580 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -862,6 +862,7 @@ struct swap_info_struct;
  *	Permit allocation of a key and assign security data. Note that key does
  *	not have a serial number assigned at this point.
  *	@key points to the key.
+ *	@flags is the allocation flags
  *	Return 0 if permission is granted, -ve error otherwise.
  * @key_free:
  *	Notification of destruction; free security data.
@@ -1324,7 +1325,7 @@ struct security_operations {
 
 	/* key management security hooks */
 #ifdef CONFIG_KEYS
-	int (*key_alloc)(struct key *key, struct task_struct *tsk);
+	int (*key_alloc)(struct key *key, struct task_struct *tsk, unsigned long flags);
 	void (*key_free)(struct key *key);
 	int (*key_permission)(key_ref_t key_ref,
 			      struct task_struct *context,
@@ -3040,9 +3041,10 @@ 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,
-				     struct task_struct *tsk)
+				     struct task_struct *tsk,
+				     unsigned long flags)
 {
-	return security_ops->key_alloc(key, tsk);
+	return security_ops->key_alloc(key, tsk, flags);
 }
 
 static inline void security_key_free(struct key *key)
@@ -3060,7 +3062,8 @@ static inline int security_key_permission(key_ref_t key_ref,
 #else
 
 static inline int security_key_alloc(struct key *key,
-				     struct task_struct *tsk)
+				     struct task_struct *tsk,
+				     unsigned long flags)
 {
 	return 0;
 }