[Bug lto/41550] New: Fix security and portability issues in lto-plugin

["dnovillo at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

>From http://gcc.gnu.org/ml/gcc-patches/2009-09/msg02151.html

> +static void
> +write_resolution (void)
> +{
> +  unsigned int i;
> +  FILE *f;
> +  /* FIXME: Disabled for now since we are not using the resolution file. */
> +  return;
> +
> +
> +  /* FIXME: This should be a temporary file. */
> +  f = fopen ("resolution", "w");

Fixed filenames like this are typically security holes.  The return above 
means this isn't, but it might be best to remove this function altogether 
until you are ready to add a version that actually does something.

> +/* Pass files generated by the lto-wrapper to the linker. FD is lto-wrapper's
> +   stdout. */
> +
> +static void
> +add_output_files (FILE *f)
> +{
> +  char fname[1000]; /* FIXME: Is this big enough? */

I don't know what sort of strings go there, but if they can be filenames 
with user-controlled components then the GNU Coding Standards say to avoid 
arbitrary limits.

> +      output_files = realloc (output_files, num_output_files * sizeof (char *));
> +      output_files[num_output_files - 1] = strdup (s);

Use xrealloc and xstrdup.  Other places have the same issue with realloc 
or calloc or strdup.

> +  /* Write argv to a file to avoid a command line that is too long. */
> +  t = asprintf (&at_args, "@%s/arguments", temp_obj_dir_name);
> +  assert (t >= 0);

This is an example of inappropriate use of assert for things that may be 
valid error conditions not a program bug.  It looks like there are others 
in this plugin.  Some cleanup work is needed.


-- 
           Summary: Fix security and portability issues in lto-plugin
           Product: gcc
           Version: lto
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
        AssignedTo: espindola at google dot com
        ReportedBy: dnovillo at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41550