[PATCH] keys: discard the contents of a key on revocation
Cause the keys linked to a keyring to be unlinked from it when revoked and it
causes the data attached to a user-defined key to be discarded when revoked.
This frees up most of the quota a key occupied at that point, rather than
waiting for the key to actually be destroyed.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index 8e71895..5bbfdeb 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -28,6 +28,7 @@
.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 @@
return ret;
} /* end user_instantiate() */
+
EXPORT_SYMBOL_GPL(user_instantiate);
/*****************************************************************************/
@@ -141,7 +143,28 @@
/*****************************************************************************/
/*
- * 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)
{