diff --git a/fs/namespace.c b/fs/namespace.c
index c7e252eb249e..de28fe9058ab 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -4976,6 +4976,11 @@ static int do_mount_setattr(const struct path *path, struct mount_kattr *kattr)
 		 * propagation.
 		 */
 		namespace_lock();
+		/* invent_group_ids() walks the tree, only walk a mounted one */
+		if (!anon_ns_root(mnt) && !check_mnt(mnt)) {
+			namespace_unlock();
+			return -EINVAL;
+		}
 		if (kattr->propagation == MS_SHARED) {
 			err = invent_group_ids(mnt, kattr->kflags & MOUNT_KATTR_RECURSE);
 			if (err) {
@@ -4988,6 +4993,7 @@ static int do_mount_setattr(const struct path *path, struct mount_kattr *kattr)
 	err = -EINVAL;
 	lock_mount_hash();
 
+	/* Checked under namespace_sem already if the propagation changes. */
 	if (!anon_ns_root(mnt) && !check_mnt(mnt))
 		goto out;