./nerdctl -n k8s.io exec -it -u root <container-id> -- sh when set -u <user>, then kernal report "lowerdir is in-use as upperdir/workdir of another mount"

### Description

./nerdctl -n k8s.io exec -it -u root -- sh
when use "nerdctl" tool exec container, set flags -u event if root, the kernal must report logs "overlayfs: lowerdir is in-use as upperdir/workdir of another mount, accessing files from both mounts will result in undefined behavior."

if not set -u , it is ok

### Steps to reproduce the issue

1. ./nerdctl -n k8s.io exec -it -u root -- sh

2.
dmesg -T logs:

### Describe the results you received and expected

when set -u , it is ok..
whichi lead to write file in container error "no such file or directory"

### What version of containerd are you using?

1.6.9, 1.6.26

### Any other relevant information

_No response_

### Show configuration if it is related to CRI plugin.

_No response_