Re: Bogus code in coffgen.c?

["H . J . Lu" <hjl at lucon dot org>]

On Thu, Nov 01, 2001 at 05:12:53PM -0800, Ian Lance Taylor wrote:
> > 
> > We allocate a buffer of `aoutsz' bytes. Then we read `internal_f.f_opthdr'
> > bytes into it. Why?
> 
> For a normal COFF target, f_opthdr should be either 0 or aoutsz.
> XCOFF is an irritating exception: XCOFF defines a large and a small
> aout header (I believe the small header is used for an object file
> while the large header is used for an executable), so for XCOFF you
> have to pay attention to f_opthdr, and not read more than that.  But
> you still want to allocate aoutsz bytes.  because that is what
> swap_aouthdr_in and friends expect, even for a small XCOFF header.
> 
> The code does the right thing for a correct object, but it's obviously
> risky for a bad object.  I think your proposed patch is appropriate;
> we may want to consider a call bfd_error_handler describing the
> problem.
> 

How about this patch? It will catch more bad files.


H.J.
----
2001-11-02  H.J. Lu  (hjl@gnu.org)

	* coffgen.c (coff_object_p): Return 0 if header is not right.

Index: coffgen.c
===================================================================
RCS file: /work/cvs/gnu/binutils/bfd/coffgen.c,v
retrieving revision 1.24
diff -u -p -r1.24 coffgen.c
--- coffgen.c	2001/10/15 20:55:56	1.24
+++ coffgen.c	2001/11/02 08:31:52
@@ -280,7 +280,8 @@ coff_object_p (abfd)
   bfd_coff_swap_filehdr_in (abfd, filehdr, &internal_f);
   bfd_release (abfd, filehdr);
 
-  if (bfd_coff_bad_format_hook (abfd, &internal_f) == false)
+  if (bfd_coff_bad_format_hook (abfd, &internal_f) == false
+      || (internal_f.f_opthdr != 0 && internal_f.f_opthdr != aoutsz))
     {
       bfd_set_error (bfd_error_wrong_format);
       return 0;