Re: Stack Shield: defending from "stack smashing" attacks

[Chris.Keane () COMLAB OX AC UK (Chris Keane)]

> > > > > On Tue, 31 Aug 1999, "CC" = Crispin Cowan wrote:

  +> So, why would one use the approach of saving the return address on
  +> another stack, instead of patching the stack itself, like StackGuard?
  +> The only reason I can imagine, is that one does not want to change the
  +> stack layout. The benefit of not changing the stack layout, is that
  +> you can do the change outside of the compiler.

  CC> Another major advantage is that gdb continues to work.  The
  CC> StackGuard method fails for all programs that introspect the stack,
  CC> gdb being the major example.

And presumably it would mean you could compile kernels with it, which also
fails with StackGuard (for Linux, at least).

Cheers,
Chris.

------------------------------------------------------------------- ><> ---
    Hardware Compilation Group, Oxford University Computing Laboratory,
            Wolfson Building, Parks Road, Oxford, OX1 3QD, U.K.
    tel:  +44 (1865) (2)73865      e-mail:  Chris.Keane () comlab ox ac uk
            http://www.comlab.ox.ac.uk/oucl/users/chris.keane/