Messages in this thread | | | From | Wolfram Gloger <> | Subject | Re: Out-of-bounds access in get_wchan (arch/x86/kernel/process_64.c) | Date | Sat, 28 Sep 2013 21:51:14 +0200 |
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Kees Cook <kees@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?
Regards, Wolfram.
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