The only ‘permissions’ bit that
git tracks is the executable bit for files, the rest of the mode bits describe what type of file system object the object in each git tree is.
git supports files and symlinks (blobs), directories (trees) and the submodules (commits).
git is designed to help track source code across different machines. Permission bits depend on user and group mappings between machines. In distributed environments where these mappings don’t exist, tracking permission bits usually ends up hindering things rather than helping anything.
If you need to track more file system attributes that what
git tracks natively you could consider and extension tool such as etckeeper.