[PATCH] keys: discard the contents of a key on revocation

[pandora-kernel.git] / security / keys / keyring.c

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 09d92d5..e8d02ac 100644 (file)
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -49,6 +49,7 @@ static inline unsigned keyring_hash(const char *desc)
 static int keyring_instantiate(struct key *keyring,
                               const void *data, size_t datalen);
 static int keyring_match(const struct key *keyring, const void *criterion);
+static void keyring_revoke(struct key *keyring);
 static void keyring_destroy(struct key *keyring);
 static void keyring_describe(const struct key *keyring, struct seq_file *m);
 static long keyring_read(const struct key *keyring,
@@ -59,6 +60,7 @@ struct key_type key_type_keyring = {
        .def_datalen    = sizeof(struct keyring_list),
        .instantiate    = keyring_instantiate,
        .match          = keyring_match,
+       .revoke         = keyring_revoke,
        .destroy        = keyring_destroy,
        .describe       = keyring_describe,
        .read           = keyring_read,
@@ -240,15 +242,16 @@ static long keyring_read(const struct key *keyring,
  * allocate a keyring and link into the destination keyring
  */
 struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
-                         int not_in_quota, struct key *dest)
+                         struct task_struct *ctx, unsigned long flags,
+                         struct key *dest)
 {
        struct key *keyring;
        int ret;
 
        keyring = key_alloc(&key_type_keyring, description,
-                           uid, gid,
+                           uid, gid, ctx,
                            (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
-                           not_in_quota);
+                           flags);
 
        if (!IS_ERR(keyring)) {
                ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL);
@@ -437,6 +440,7 @@ EXPORT_SYMBOL(keyring_search);
 /*
  * search the given keyring only (no recursion)
  * - keyring must be locked by caller
+ * - caller must guarantee that the keyring is a keyring
  */
 key_ref_t __keyring_search_one(key_ref_t keyring_ref,
                               const struct key_type *ktype,
@@ -479,51 +483,6 @@ key_ref_t __keyring_search_one(key_ref_t keyring_ref,
 
 } /* end __keyring_search_one() */
 
-/*****************************************************************************/
-/*
- * search for an instantiation authorisation key matching a target key
- * - the RCU read lock must be held by the caller
- * - a target_id of zero specifies any valid token
- */
-struct key *keyring_search_instkey(struct key *keyring,
-                                  key_serial_t target_id)
-{
-       struct request_key_auth *rka;
-       struct keyring_list *klist;
-       struct key *instkey;
-       int loop;
-
-       klist = rcu_dereference(keyring->payload.subscriptions);
-       if (klist) {
-               for (loop = 0; loop < klist->nkeys; loop++) {
-                       instkey = klist->keys[loop];
-
-                       if (instkey->type != &key_type_request_key_auth)
-                               continue;
-
-                       rka = instkey->payload.data;
-                       if (target_id && rka->target_key->serial != target_id)
-                               continue;
-
-                       /* the auth key is revoked during instantiation */
-                       if (!test_bit(KEY_FLAG_REVOKED, &instkey->flags))
-                               goto found;
-
-                       instkey = ERR_PTR(-EKEYREVOKED);
-                       goto error;
-               }
-       }
-
-       instkey = ERR_PTR(-EACCES);
-       goto error;
-
-found:
-       atomic_inc(&instkey->usage);
-error:
-       return instkey;
-
-} /* end keyring_search_instkey() */
-
 /*****************************************************************************/
 /*
  * find a keyring with the specified name
@@ -996,3 +955,22 @@ int keyring_clear(struct key *keyring)
 } /* end keyring_clear() */
 
 EXPORT_SYMBOL(keyring_clear);
+
+/*****************************************************************************/
+/*
+ * dispose of the links from a revoked keyring
+ * - called with the key sem write-locked
+ */
+static void keyring_revoke(struct key *keyring)
+{
+       struct keyring_list *klist = keyring->payload.subscriptions;
+
+       /* adjust the quota */
+       key_payload_reserve(keyring, 0);
+
+       if (klist) {
+               rcu_assign_pointer(keyring->payload.subscriptions, NULL);
+               call_rcu(&klist->rcu, keyring_clear_rcu_disposal);
+       }
+
+} /* end keyring_revoke() */