How to mount SMB share that can be accessed by anyone on Mac OS X El Capitan

Make the SMB share mountable as guest, then it will be mounted with right permissions.

I had the exact same problem and this works for me in High Sierra:

/etc/auto_nfs:

Public -fstype=smbfs,soft,noowners,noatime,nosuid smb://[email protected]/Public

And after mount, it will have drwxrwxrwx rights and I am able to browse it from different users.

It seems like macOS does not allow users to mount SMB network drive with custom uid/gid bits. And it only permits a user who mounts a drive to access the drive. I do not know whether Apple cares about security or it is just a bug. But unfortunately, it is for years. I have tested several cases on a macOS-to-macOS shared drive:

    known-user@a-server:~% sudo ls -l
    -rw-r-----  1 known-user    known-group    0 Jun 13 10:50 a-file
    -rw-r-----  1 known-user    unknown-group  0 Jun 13 10:50 b-file
    -rw-r-----  1 unknown-user  known-group    0 Jun 13 10:50 c-file
    -rw-r-----  1 unknown-user  unknown-group  0 Jun 13 10:50 b-file

    who-mount@my-desktop:~% sudo ls -l
    -rw-r-----  1 who-mount     whose-group  0 Jun 13 10:50 a-file
    -rw-r-----  1 who-mount     whose-group  0 Jun 13 10:50 b-file
    -rw-r-----  1 who-mount     whose-group  0 Jun 13 10:50 c-file
    -rw-r-----  1 who-mount     whose-group  0 Jun 13 10:50 d-file

    who-mount@my-desktop:~% cat a-file
    who-mount@my-desktop:~% echo hello > a-file

    who-mount@my-desktop:~% cat b-file
    who-mount@my-desktop:~% echo hello > b-file

    who-mount@my-desktop:~% cat c-file
    who-mount@my-desktop:~% echo hello > c-file
    zsh: permission denied: c-file

    who-mount@my-desktop:~% cat d-file
    cat: d-file: Permission denied
    who-mount@my-desktop:~% echo hello > d-file
    zsh: permission denied: d-file

1. The uid/gid of shared files/folders are always who-mount:whose-group
2. The permission bits are the same on the shared server a-server
3. The server treats who-mount as known-user:known-group (here known-group is the default group of know-user)

One suggestion is to use Fuse for macOS. It provides custom uid/gid and permission bits options with -o flag; check out bindfs which mounts FUSE drive and alters permission. With the bindfs, you can mount permission-fetched smb drive after mounting the smb drive in the way you mentioned.

But, I think, the best is each user has own shared drives.