[Samba] access to files continues after removing user from group
jra at samba.org
Wed May 11 16:07:28 UTC 2016
On Wed, May 11, 2016 at 11:00:49AM -0500, Chad William Seys wrote:
> Hi Jeremy,
> > The kernel checks the token attached to the process
> > at the time the process accesses the filesystem/resource.
> > This is how OS'es work. It's how they *all* work.
> > What you're complaining about is that changes to
> > the database that is used to create the process
> > token doesn't dynamically update running process
> > tokens.
> > That just not the way running processes work
> > I'm afraid.
> Well I'll be! I verified that this is the case for netatalk as well. I am
> surprised the security minded haven't gone bonkers over this. I wonder what
> reason(s) keep them pacified?
Because that's just the way the process model works.
> I still don't understand why removing a user from group does not take effect
> until a new process starts
> BUT ADDING a user to the group takes effect immediately.
> Isn't this inconsistent with the "no dynamic updates to running processes"
Adding a user to a group won't change the token on existing
proceses. If a user attaches to Samba after that user is
added to the group will create a new token attached to
the new smbd process. It won't change any existing smbd
More information about the samba