[PATCH] keys: discard the contents of a key on revocation
[linux-2.6.git] / security / keys / user_defined.c
index 8e71895b97a7eaa90c4aee3088794d5b827a7cd6..5bbfdebb7acfb79436d615851ec91d57c2d74c49 100644 (file)
@@ -28,6 +28,7 @@ struct key_type key_type_user = {
        .instantiate    = user_instantiate,
        .update         = user_update,
        .match          = user_match,
+       .revoke         = user_revoke,
        .destroy        = user_destroy,
        .describe       = user_describe,
        .read           = user_read,
@@ -67,6 +68,7 @@ error:
        return ret;
 
 } /* end user_instantiate() */
+
 EXPORT_SYMBOL_GPL(user_instantiate);
 
 /*****************************************************************************/
@@ -141,7 +143,28 @@ EXPORT_SYMBOL_GPL(user_match);
 
 /*****************************************************************************/
 /*
- * dispose of the data dangling from the corpse of a user
+ * dispose of the links from a revoked keyring
+ * - called with the key sem write-locked
+ */
+void user_revoke(struct key *key)
+{
+       struct user_key_payload *upayload = key->payload.data;
+
+       /* clear the quota */
+       key_payload_reserve(key, 0);
+
+       if (upayload) {
+               rcu_assign_pointer(key->payload.data, NULL);
+               call_rcu(&upayload->rcu, user_update_rcu_disposal);
+       }
+
+} /* end user_revoke() */
+
+EXPORT_SYMBOL(user_revoke);
+
+/*****************************************************************************/
+/*
+ * dispose of the data dangling from the corpse of a user key
  */
 void user_destroy(struct key *key)
 {