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

macos mac permissions smb osx-el-capitan

17,361

Solution 1

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.

Solution 2

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

The uid/gid of shared files/folders are always who-mount:whose-group
The permission bits are the same on the shared server a-server
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.

17,361

Rytis I

Updated on September 18, 2022

Comments

Rytis I over 1 year
How can I mount a SMB network share that can be accessed by anyone? Here's what I tried:

Using mount command
```
me$ sudo mkdir /Multimedia
me$ sudo chmod 777 /Multimedia
me$ sudo mount -t smbfs -o nosuid,-d=777 //user:password@qnap/Multimedia /Multimedia/
```
then
```
me$ cd /Multimedia      
-bash: cd: /Multimedia: Permission denied
```
permission on /Multimedia after mounting
```
drwxrwxrwx   1 root  wheel  16384 Nov  8 11:04 Multimedia
```
yet this works
```
root# cd /Multimedia
```
tl;dr only root can access mounted share

Using automount

in /etc/auto_master
```
#
# Automounter master map
#
+auto_master            # Use directory service
/net                    -hosts          -nobrowse,hidefromfinder,nosuid
/home                   auto_home       -nobrowse,hidefromfinder
/Network/Servers        -fstab
/-                      -static
### SMB shares
/-                      /etc/automounts/smb -nosuid,noowners
```
in /etc/automounts/smb
```
/Multimedia        -fstype=smbfs,soft,noowners,noatime,nosuid ://user:password@qnap/Multimedia
```
then
```
me$ sudo automount -vc
automount: /net updated
automount: /home updated
automount: /Multimedia mounted
automount: no unmount
```
after that
```
me$ cd /Multimedia
me$ ls -ld /Multimedia/
drwx------  1 me  staff  16384 Nov  8 11:04 /Multimedia/
```
Works! But unfortunately other users have no access
```
otheruser$ cd /Multimedia 
-bash: cd: /Multimedia: Permission denied
```
Yet if I
```
me$ umount /Multimedia
```
and then
```
otheruser$ cd /Multimedia
otheruser$ ls -ld /Multimedia 
drwx------  2 otheruser  staff  1 Nov  8 15:17 /Multimedia
```
Works! But
```
me$ cd /Multimedia
-bash: cd: /Multimedia: Permission denied
```
and yet
```
root# cd /Multimedia
```
Works!

tl;dr only the user that caused automount and root have access to the share
- techraf over 8 years
  
  Verified your first method and found no problem. I could mount and access the share with root, me, and other user. After mounting regardless of noowners or nosuid flags I always got the current user as owner and staff as group on a mount point. (btw you've got a typo nowness in /etc/auto_master)
- Rytis I over 8 years
  
  @techraf good catch! Thanks for verifying, it's very strage that you've got a different result. Could the permission of the share itself have something to do with it? I'll try to mess with it tonight
- HankCa almost 8 years
  
  Hi @Rytis l, I have the same problem - did you work this out?
- Rytis I almost 8 years
  
  @HankCa nope, still have this issue :(
- The Lazy Log over 7 years
  
  I wonder if you have figured out a way to resolve this issue?
- Rytis I over 7 years
  
  @TheLazyLog nope :(
- IceFire about 4 years
  
  Also in here, wondering if this could work some way. Although drwxrwxrwx is set, other users cannot access... what dark magic is this?
Rytis I almost 7 years

Not sure if this covers my use case. The idea is that the share needs to be mounted on OS startup for every user. But I'll try it out and report back
Rytis I almost 7 years

OK so "Sharing" shares a Folder from mac to others. What I'm trying is achieve is the opposite. I'm trying to mount an existing network share to my mac.
Marc Augier almost 7 years

All right, then you want to share a folder from Linux ? Qorry, I was looking in the wrong dirction ^_^ I did that on a Debian system as well. I am may be too lazy but instead of CLI I used as well the Gnome preference panel in order to activate sharing on a folder.