ACL
pode ajudar:
# Create shared directory
sudo mkdir -p /media/Shared
# Give user1 and user2 rwX access to /media/Shared
sudo setfacl -m u:user1:rwX '/media/Shared'
sudo setfacl -m u:user2:rwX '/media/Shared'
# Make rwX access the default for new files and folders for both users
sudo setfacl -m default:u:user1:rwX '/media/Shared'
sudo setfacl -m default:u:user2:rwX '/media/Shared'
Altere user1
, user2
e /media/Shared
de acordo com suas necessidades.