Re: revert PIE randomization?

From: Kees Cook
Date: Wed Mar 21 2007 - 14:18:47 EST


Hi Hugh,

Hugh Dickins said:
> Inconsistency detected by ld.so: rtld.c: 1217: dl_main:
> Assertion `_rtld_local._dl_rtld_map.l_libname' failed!

I'm trying to reproduce the problem you saw (so that I can then test
your proposed fix). However, I haven't had any luck. I've got a
pie-compiled version of bash, and I've been running it in a loop for a
while now with the original randomization patch. (I can clearly see the
base address bouncing around.)

I'm at just over 10 million exec's, and I haven't hit the problem. :(

Do you have any clues on how to trigger this more reliably?

Also, does anyone have any thoughts on why x86 uses a ELF_ET_DYN_BASE
below the libraries, where as x86_64 uses one above them? From this,
I'd expect x86_64 to collide with the libraries at times. I need more
help understanding the memory layouts, I guess. :)

Thanks,

--
Kees Cook @outflux.net
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