[PATCH 1/2] Cygwin: format_process_fd: add directory check

[Corinna Vinschen]

Hi Ken,

On Sep  8 12:50, Ken Brown via Cygwin-patches wrote:
> The incoming path is allowed to have the form "$PID/fd/[0-9]*/.*"
> provided the descriptor symlink points to a directory.  Check that
> this is indeed the case.
> ---
>  winsup/cygwin/fhandler_process.cc | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/winsup/cygwin/fhandler_process.cc b/winsup/cygwin/fhandler_process.cc
> index a6c358217..888604e3d 100644
> --- a/winsup/cygwin/fhandler_process.cc
> +++ b/winsup/cygwin/fhandler_process.cc
> @@ -398,6 +398,21 @@ format_process_fd (void *data, char *&destbuf)
>  	*((process_fd_t *) data)->fd_type = virt_fdsymlink;
>        else /* trailing path */
>  	{
> +	  /* Does the descriptor link point to a directory? */
> +	  bool dir;
> +	  if (*destbuf != '/')	/* e.g., "pipe:[" or "socket:[" */
> +	    dir = false;
> +	  else
> +	    {
> +	      path_conv pc (destbuf);
> +	      dir = pc.isdir ();
> +	    }
> +	  if (!dir)
> +	    {
> +	      set_errno (ENOTDIR);
> +	      cfree (destbuf);
> +	      return -1;
> +	    }
>  	  char *newbuf = (char *) cmalloc_abort (HEAP_STR, strlen (destbuf)
>  							   + strlen (e) + 1);
>  	  stpcpy (stpcpy (newbuf, destbuf), e);
> -- 
> 2.28.0

Huh, I'd never realized this check is missing.  I was just puzzeling
over your patch, searching for the directory check, but yeah, there is
none.  Please push.


Thanks,
Corinna