[Pkg-samba-maint] Bug#1019545: samba: Permission/ownership issue in /var/lib/samba results in repeated panic or segfault after upgrading from Buster to Bullseye

[Michael Tokarev]

15.09.2022 13:17, Michael Tokarev wrote:
...
> Now, I don't know which permissions/ownership you files *had* before you changed them.  Please
> note how this directory is being created:
> 
>     install -d -m 1770 -g sambashare /var/lib/samba/usershares
> 
> The "1" "sticky" bit tells the kernel to use the same group for all subdirectories and files
> created within. So you should not need to change the group ownership in the first place. If
> you had to, it means this sticky bit hasn't been there in your case. Which, in turn, means
> some local modification you did, probably.

This is ofc incorrect, sticky bit has nothing to do with the group
ownership.

Now, the files *within* /var/lib/samba/usershares/ dir should belong to whatever
user/group who created them, definitely not to root:sambashare. More, if these
belong to root, usershare owner only (default yes) will prevent removing/modifying
shares by using `net usershare' command.  Only this directory itself should belong
to group sambashare.

And your user definitely should have write access to this directory in order to *add*
share definitions by using `net usershare add' etc commands.  Not for *using* the
already defined shares but to *add* them.

> Either way, after you actually changed the ownership/permission bits, it's impossible to
> see what the actual problem was.

I still don't know which ownership/permissions you did have.  I tried to replicate
this issue, - I can trigger this warning in the smbd logfile:

[2022/09/15 14:06:28.521611,  0] ../../source3/param/loadparm.c:3454(process_usershare_file)
   process_usershare_file: stat of /var/lib/samba/usershares/data failed. Permission denied

but there's no crashes, it is just a warning.

So it must be something specific to your configuration.

/mjt