[1/6] KEYS: Authorise keyctl_set_timeout() on a key if we have its authorisation key

Commit Message

David Howells July 22, 2010, 5:32 p.m. UTC

None

Patch

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 6261745..639226a 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1091,7 +1091,7 @@  error:
 long keyctl_set_timeout(key_serial_t id, unsigned timeout)
 {
 	struct timespec now;
-	struct key *key;
+	struct key *key, *instkey;
 	key_ref_t key_ref;
 	time_t expiry;
 	long ret;
@@ -1099,10 +1099,25 @@  long keyctl_set_timeout(key_serial_t id, unsigned timeout)
 	key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
 				  KEY_SETATTR);
 	if (IS_ERR(key_ref)) {
+		/* setting the timeout on a key under construction is permitted
+		 * if we have the authorisation token handy */
+		if (PTR_ERR(key_ref) == -EACCES) {
+			instkey = key_get_instantiation_authkey(id);
+			if (!IS_ERR(instkey)) {
+				key_put(instkey);
+				key_ref = lookup_user_key(id,
+							  KEY_LOOKUP_PARTIAL,
+							  0);
+				if (!IS_ERR(key_ref))
+					goto okay;
+			}
+		}
+
 		ret = PTR_ERR(key_ref);
 		goto error;
 	}
 
+okay:
 	key = key_ref_to_ptr(key_ref);
 
 	/* make the changes with the locks held to prevent races */