Re: is_absolute_path incorrect on Windows

Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > Tom Lane wrote:
> >> Bruce Momjian <bruce@momjian.us> writes:
> >>> I have reviewed is_absolute_path() and have implemented
> >>> path_is_relative_and_below_cwd() to cleanly handle cases like 'E:abc' on
> >>> Win32;  patch attached.
> >> 
> >> This patch appears to remove some security-critical restrictions.
> >> Why did you delete the path_contains_parent_reference calls?
> 
> > They are now in path_is_relative_and_below_cwd(),
> 
> ... and thus not invoked in the absolute-path case.  This is a security
> hole.
> 
> >  I don't see a general reason to prevent
> > ".." in absolute paths, only relative ones.
> 
> 	load '/path/to/database/../../../path/to/anywhere'

Ah, good point. I was thinking about someone using ".." in the part of
the path that is compared to /data or /log, but using it after that
would clearly be a security problem.

I have attached an updated patch that restructures the code to be
clearer and adds the needed checks.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +