1 files changed, 34 insertions, 27 deletions

diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 09541de31f2f..b5d5333ab330 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -465,7 +465,7 @@ key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx)
 		case -EAGAIN: /* no key */
 			if (ret)
 				break;
-			/* fall through */
+			fallthrough;
 		case -ENOKEY: /* negative key */
 			ret = key_ref;
 			break;
@@ -487,7 +487,7 @@ key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx)
 		case -EAGAIN: /* no key */
 			if (ret)
 				break;
-			/* fall through */
+			fallthrough;
 		case -ENOKEY: /* negative key */
 			ret = key_ref;
 			break;
@@ -509,7 +509,7 @@ key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx)
 		case -EAGAIN: /* no key */
 			if (ret)
 				break;
-			/* fall through */
+			fallthrough;
 		case -ENOKEY: /* negative key */
 			ret = key_ref;
 			break;
@@ -609,7 +609,7 @@ bool lookup_user_key_possessed(const struct key *key,
  * returned key reference.
  */
 key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
-			  key_perm_t perm)
+			  enum key_need_perm need_perm)
 {
 	struct keyring_search_context ctx = {
 		.match_data.cmp		= lookup_user_key_possessed,
@@ -773,35 +773,34 @@ try_again:
 
 	/* unlink does not use the nominated key in any way, so can skip all
 	 * the permission checks as it is only concerned with the keyring */
-	if (lflags & KEY_LOOKUP_FOR_UNLINK) {
-		ret = 0;
-		goto error;
-	}
-
-	if (!(lflags & KEY_LOOKUP_PARTIAL)) {
-		ret = wait_for_key_construction(key, true);
-		switch (ret) {
-		case -ERESTARTSYS:
-			goto invalid_key;
-		default:
-			if (perm)
+	if (need_perm != KEY_NEED_UNLINK) {
+		if (!(lflags & KEY_LOOKUP_PARTIAL)) {
+			ret = wait_for_key_construction(key, true);
+			switch (ret) {
+			case -ERESTARTSYS:
+				goto invalid_key;
+			default:
+				if (need_perm != KEY_AUTHTOKEN_OVERRIDE &&
+				    need_perm != KEY_DEFER_PERM_CHECK)
+					goto invalid_key;
+				break;
+			case 0:
+				break;
+			}
+		} else if (need_perm != KEY_DEFER_PERM_CHECK) {
+			ret = key_validate(key);
+			if (ret < 0)
 				goto invalid_key;
-		case 0:
-			break;
 		}
-	} else if (perm) {
-		ret = key_validate(key);
-		if (ret < 0)
+
+		ret = -EIO;
+		if (!(lflags & KEY_LOOKUP_PARTIAL) &&
+		    key_read_state(key) == KEY_IS_UNINSTANTIATED)
 			goto invalid_key;
 	}
 
-	ret = -EIO;
-	if (!(lflags & KEY_LOOKUP_PARTIAL) &&
-	    key_read_state(key) == KEY_IS_UNINSTANTIATED)
-		goto invalid_key;
-
 	/* check the permissions */
-	ret = key_task_permission(key_ref, ctx.cred, perm);
+	ret = key_task_permission(key_ref, ctx.cred, need_perm);
 	if (ret < 0)
 		goto invalid_key;
 
@@ -919,6 +918,13 @@ void key_change_session_keyring(struct callback_head *twork)
 		return;
 	}
 
+	/* If get_ucounts fails more bits are needed in the refcount */
+	if (unlikely(!get_ucounts(old->ucounts))) {
+		WARN_ONCE(1, "In %s get_ucounts failed\n", __func__);
+		put_cred(new);
+		return;
+	}
+
 	new->  uid	= old->  uid;
 	new-> euid	= old-> euid;
 	new-> suid	= old-> suid;
@@ -928,6 +934,7 @@ void key_change_session_keyring(struct callback_head *twork)
 	new-> sgid	= old-> sgid;
 	new->fsgid	= old->fsgid;
 	new->user	= get_uid(old->user);
+	new->ucounts	= old->ucounts;
 	new->user_ns	= get_user_ns(old->user_ns);
 	new->group_info	= get_group_info(old->group_info);