- uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx,
- KEY_ALLOC_IN_QUOTA, session_keyring);
- if (IS_ERR(uid_keyring)) {
- key_put(session_keyring);
- ret = PTR_ERR(uid_keyring);
- goto error;
+ if (!user->uid_keyring) {
+ /* get the UID-specific keyring
+ * - there may be one in existence already as it may have been
+ * pinned by a session, but the user_struct pointing to it
+ * may have been destroyed by setuid */
+ sprintf(buf, "_uid.%u", user->uid);
+
+ uid_keyring = find_keyring_by_name(buf, true);
+ if (IS_ERR(uid_keyring)) {
+ uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1,
+ tsk, KEY_ALLOC_IN_QUOTA,
+ NULL);
+ if (IS_ERR(uid_keyring)) {
+ ret = PTR_ERR(uid_keyring);
+ goto error;
+ }
+ }
+
+ /* get a default session keyring (which might also exist
+ * already) */
+ sprintf(buf, "_uid_ses.%u", user->uid);
+
+ session_keyring = find_keyring_by_name(buf, true);
+ if (IS_ERR(session_keyring)) {
+ session_keyring =
+ keyring_alloc(buf, user->uid, (gid_t) -1,
+ tsk, KEY_ALLOC_IN_QUOTA, NULL);
+ if (IS_ERR(session_keyring)) {
+ ret = PTR_ERR(session_keyring);
+ goto error_release;
+ }
+
+ /* we install a link from the user session keyring to
+ * the user keyring */
+ ret = key_link(session_keyring, uid_keyring);
+ if (ret < 0)
+ goto error_release_both;
+ }
+
+ /* install the keyrings */
+ user->uid_keyring = uid_keyring;
+ user->session_keyring = session_keyring;