On Sat, Sep 28, 2013 at 09:51:14PM +0200, Wolfram Gloger wrote: > Kees Cook <k...@outflux.net> writes: > > > Please note that these bounds checks aren't correct to begin with. Since > > a pointer is being dereferenced, the end boundry must be reduced by > > sizeof(unsigned long) as well. > > > > It looks like process_32.c suffers the same problems, too. > > I can't see the end boundary problem in process_32.c. The end checks > are properly reduced with the top_esp and top_ebp macros. > > All I can see in process_32.c is that the check > > if (bp < stack_page || bp > top_ebp+stack_page) > > could be replaced by: > > if (bp < stack_page-sizeof(unsigned long) || bp > > top_ebp+stack_page) > > but that is a relaxation and not an over/underrun fix. > > Can you elaborate what problem you see in process_32.c?
Ah, yes, sorry, this appears to only be a problem in process_64.c. I didn't look closely enough. I see now that top_esp and top_ebp correctly reduce the size of THREAD_SIZE. Thanks! -Kees -- Kees Cook @outflux.net -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
