Re: [Fwd: Obscure problem with Bash when printing]

[James Richard Tyrer]

Francis Litterio wrote:
> James Richard Tyrer wrote:
>
>
> > > While this is an obscure problem.  It is a very serious bug since Bash does
> > > not correctly set HOME to match the user as reported by:
> > >    id -un
> >
> > I thought that I should clarify that this ONLY happens when the LPR daemon
> > (which is running as root) calls the filter script (as the user that submitted
> > the job) that HOME is not correctly set to the: "passwd" file entry for the
> > user.
>
>
> An examination of the source code (file variables.c) shows that Bash
> sets HOME only if it's not already in the environment:
>
>     /* Set $HOME to the information in the password file if we didn't get
>        it from the environment. */
>
>     ...
>
>     static void
>     set_home_var ()
>     {
>       SHELL_VAR *temp_var;
>
>       temp_var = find_variable ("HOME");
>       if (temp_var == 0)
>         temp_var = bind_variable ("HOME", sh_get_home_dir ());
>     #if 0
>       VSETATTR (temp_var, att_exported);
>     #endif
>     }
>
> Thus, it is the LPR daemon that is not changing HOME before exec'ing the
> filter script.

I have changed the filter script to a login script, which is necessary for it 
to set the
GS environment strings and it sets HOME to "/".

I think that this is the relevant code in: "shell.c":

void
get_current_user_info()
{
  struct passwd *entry;

  /* Don't fetch this more than once. */
  if(current_user.user_name == 0)
    {
      entry = getpwuid(current_user.uid);
      if(entry)
        {
          current_user.user_name = savestring(entry->pw_name);
          current_user.shell = (entry->pw_shell && entry->pw_shell[0])
                                ? savestring(entry->pw_shell)
                                : savestring("/bin/sh");
          current_user.home_dir = savestring(entry->pw_dir);
        }
      else
        {
          current_user.user_name = savestring("I have no name!");
          current_user.shell = savestring("/bin/sh");
          current_user.home_dir = savestring("/");
        }
      endpwent();
    }
}

I can't see how this doesn't work. :-\

It won't help for LPR to set HOME, because the login will change it.

--
JRT