Linux – Access Samba share from Windows 10 in VirtualBox

linuxnetworkingsambavirtualboxwindows 10

I read a lot of user questions and blogs about this concern, but nothing fixed my issue.

I have a Linux CENTOS host with Windows 10 guest installed in VirtualBox. On Linux, there's a user named "myuser" which shares a directory (777) and is registred to Samba user database. This user has no password restriction. The smb.conf looks like this:

[global]
workgroup = WORKSPACE_SHARE
security = user
map to guest = bad user

[public]
path = /home/myuser/public
public = yes
writeable = yes
comment = smb share
printable = no
guest ok = yes

Windows has a local user with the same name ("myuser", no password set), file and printer sharing enabled, Microsoft Client enabled, workgroup set which matches the Samba workgroup and uses a private network.

In explorer I can see the Linux host which, indeed, contains the shared folder ("public"). But when a try to access this shared folder, an error alert appears: You do not have permissions to access…

On the internet I read things like "Windows 10 uses SMBv3 but Samba doesn't yet support it" and how to turn SMBv3 off – but it didn't help.

Even modification of Local Security Policies on Windows didn't do the trick: https://superuser.com/a/916835/408191

How can I fix this weird issue?

Best Answer

Some Linux distributions have a so called SELinux implementation in its kernel. It stands for "Security-Enhanced Linux" and, beside other things, restricts Samba shares. If you want to create a share folder then it's not not enough to specify convenient access permissions and a definition in samba.conf. You also need to set the correct "Security Context" of the share folder.

Following permission mask and security context should do the trick:

chmod -R 770 yoursharefolder
chcon -R -t samba_share_t yoursharefolder

All conditions that are already known from different wikis must also be adhered:

Unix user as owner of the share must be added to Samba user database: smbpasswd -a youruser
Your windows machine must have a user with the same name and same password as set in Samba database
Your samba.conf may look like this:

samba.conf (all upper-case parts must be customized for your concerning specific environment):

[global]
workgroup = SAME_WORKGROUP_AS_CONFIGURED_IN_WINDOWS
server string = Samba Server %v
netbios name = HOST_NAME_OF_YOUR_LINUX_MACHINE_ON_NETWORK
security = user
map to guest = bad user
dns proxy = no

[yourshare]
path = /PATH/TO/YOURSHARE
valid users = YOUR_WINDOWS_USER_NAME
browsable = yes
writeable = yes
guest ok = no
read only = no
directory mask = 0770
create mask = 0770

Edit: Note that changes via chcon aren't permanent. In order to do permanent security context changes use following command:

semanage fcontext -a -t samba_share_t /full/path/to/your/share/folder

...and to make it effective:

restorecon -v /full/path/to/your/share/folder

Related Solutions

Linux – Using Samba to share a folder from a Linux guest with a Windows host in VirtualBox

These are examples how you define a share in your smb.conf

[readonly-share]
   comment = some share
   path = /this/folder/is/shared
   guest ok = no
   browseable = yes
   read only = yes

[read-write-share]
   comment = another share
   path = /this/folder/is/writable
   guest ok = no
   browseable = yes
   read only = no
   create mask = 0777
   directory mask = 0777
   force create mode = 777
   force directory mode = 777
   force security mode = 777
   force directory security mode = 777

After you edit smb.conf run "testparm" to check your changes, then let the daemon re-read the config with a "service smbd restart"
(Not sure about this one)
With a "NAT" and "host-only" virtual network card you should be safe. To reach the guest's services from any other computer but the host, you would need to set up port forwardings on the host or configure a "bridged" virtual network card.
Authentication type can be set in the smb.conf. The default setting in Ubuntu's samba conf it to set "security = user", which means that you have to authenticate with a valid useraccount. (unless you have set "guest ok = yes")

To access the shares from your Windows Host you have to use the guest's IP address. VBox NATs are use addresses like "10.0.2.15". To reach the share "readonly-share" from the host you can write a URI like this in the File Explorer's address bar:
```
\\10.0.2.15\readonly-share
```

Windows – How to allow guest access in SAMBA

In order to set up guest access in Samba, you need to set up a user that it will pretend to log in as. So, let's say you want to share files on /mnt/somepartition/files publically. Your configuration might look like this:

[public_files]
    comment = Public files
    path = /mnt/somepartition/files
    browsable = yes
    guest ok = yes
    writable = yes
    guest account = someusername
    create mask = 0775
    directory mask = 0755

What this saying is "Create a samba share on \mymachine\public_files that is viewable to anonymous users (not hidden like user files generally are) and enable it for write access. Anonymous users can access this share by using someusername's credentials. When files are created, make them globally executable but restrict write access globally. When directories are created, make them globally executable but only writable by someusername."

Once this is done, you will need to create a smbpassword, per your question. To do this, ensure first that the user exists within your server. If the user doesn't, create it:

sudo adduser someusername

Once the user exists, create a samba login:

sudo smbpasswd -a someusername

A couple of things to keep in mind: the directory that public_files points to will need to be READ accessible to someusername. Make sure you set the permissions correctly. If the directory is owned by you but still want to make them available, add someusername to a common group and then change the group ownership.

Best Answer

Related Solutions

Linux – Using Samba to share a folder from a Linux guest with a Windows host in VirtualBox

Windows – How to allow guest access in SAMBA

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