[6.8.3] [6.9.0] [6.9.1] shfs seems to ignore permissions

create a test directory in /mnt/user/Downloads

root@MediaStore:/mnt/user/Downloads# ls -al test
total 0
drwx------ 1 root   root       0 Jan 20 23:33 ./
drwxrws--- 1 nobody users 205274 Jan 20 23:33 ../
root@MediaStore:/mnt/user/Downloads# ls -ld /mnt/{cache,user}/Downloads
drwxrws--- 1 nobody users 205274 Jan 20 23:33 /mnt/cache/Downloads/
drwxrws--- 1 nobody users 205274 Jan 20 23:33 /mnt/user/Downloads/

when this directory is mounted in a container like so

root@MediaStore:~# docker run --rm --name box -d -v /mnt/cache/Downloads:/media alpine sleep 3600
131ed3b6357ba8253513afc5e536361adf39de6ac5ca26ccdf22337770d60c76
root@MediaStore:~# docker exec -u 1002 -it box sh -c 'id; ls -ld /media; touch /media/a_file && ls -l /media/a_file'
uid=1002 gid=0(root)
drwxrws---    1 99       users       205274 Jan 20 15:33 /media
touch: /media/a_file: Permission denied
root@MediaStore:~# docker stop box
box
root@MediaStore:~# docker run --rm --name box -d -v /mnt/user/Downloads:/media alpine sleep 3600
0dc76c0b4c8c6cf3f7b05c998a96e96a18e6f394e0e0bada60b66db3225c17c8
root@MediaStore:~# docker exec -u 1002 -it box sh -c 'id; ls -ld /media; touch /media/a_file && ls -l /media/a_file'
uid=1002 gid=0(root)
drwxrws---    1 99       users       205274 Jan 20 15:33 /media
-rw-r--r--    1 1002     root             0 Jan 20 15:40 /media/a_file
root@MediaStore:~# docker stop box
box

Seems like when the path is mounted via the user share path, the file permissions can be ignored in a specific situation

Edit:

It seems to be shfs itself - since the following issue occurs at the Unraid level

root@MediaStore:/mnt/user/Downloads# echo x > a
root@MediaStore:/mnt/user/Downloads# chmod 600 a
root@MediaStore:/mnt/user/Downloads# ls -l a
-rw------- 1 root root 2 Mar 23 21:44 a
root@MediaStore:/mnt/user/Downloads# ls -l /mnt/cache/Downloads/a
-rw------- 1 root root 2 Mar 23 21:44 /mnt/cache/Downloads/a
root@MediaStore:/mnt/user/Downloads# cat a
x
root@MediaStore:/mnt/user/Downloads# su nobody -s /bin/sh
nobody@MediaStore:/mnt/user/Downloads$ cat a
x
nobody@MediaStore:/mnt/user/Downloads$ cat /mnt/cache/Downloads/a
cat: /mnt/cache/Downloads/a: Permission denied
nobody@MediaStore:/mnt/user/Downloads$ echo y > a
nobody@MediaStore:/mnt/user/Downloads$ cat a
y

mediastore-diagnostics-20210120-2344.zip