BUG: Wide Links - does not work as documented

[Cole, Timothy D.]

> -----Original Message-----
> From:	Cole, Timothy D. 
> Sent:	Tuesday, April 18, 2000 10:58
> To:	Multiple recipients of list SAMBA-TECHNICAL
> Subject:	RE: BUG: Wide Links - does not work as documented
> 
> > -----Original Message-----
> > From:	Jani Jaakkola [SMTP:jjaakkol at cs.helsinki.fi]
> > Sent:	Thursday, April 13, 2000 15:05
> > To:	Multiple recipients of list SAMBA-TECHNICAL
> > Subject:	Re: BUG: Wide Links - does not work as documented
> > 
> > On Thu, 13 Apr 2000, Jeremy Allison wrote:
> > 
> > > Not at all portable I'm afraid.
> > 
> > Right. So for systems which do not have O_NOFOLLOW:
> > 
> > 1. lstat() the filename. If it is a symlink, return failure
> > 2. open the file (without O_NOFOLLOW)
> > 3. fstat() the filedescriptor returned by open.
> > 4. If the fstat() and lstat() did not agree (they did not point to same
> >    inode), we had a race condition situation. Close the
> >    already opened file and return failure. 
> > 
> 	What happens if you inadvertantly opened, say, /etc/passwd with
> O_TRUNCATE?  By the time you do the fstat(), you're already SOL.
> 
	Actually /etc/password, was a bad example.  Let's just say some file
outside the exported tree that the [remote] user shouldn't have write access
to but does... which contains some sort of valuable data.

	[ of course, this raises the question as to why permissions weren't
set right in the first place ]