[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 e81ebf910d0b..e693e729bc92 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 d2c17bd91a29..51805806f974 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;
 }