Re: [PATCH] [RESEND] PIE executable randomization

From: Chuck Ebbert
Date: Wed Aug 15 2007 - 13:40:45 EST


On 08/14/2007 04:41 PM, Jiri Kosina wrote:
> (added Arjan to CC, as he has been working on the kernel part of the
> randomization previously)
>
> On Tue, 14 Aug 2007, Jakub Jelinek wrote:
>
>> If I'm reading the above hunk correctly, this means we will randomize
>> all PIEs and even all dynamic linkers invoked as executables on i?86 and
>> x86_64, and on the rest of arches we won't randomize at all, instead
>> load ET_DYN objects at ELF_ET_DYN_BASE address. But I don't see anything
>> i?86/x86_64 specific on this.
>
> Hi Jakub,
>
> actually, it is currently arch-specific, and that's because of different
> memory layouts on different archs.
>
> It turned out recently that PIE-compiled binaries on x86_64, that perform
> larger amount of brk-allocations (for example bash) will not work (but
> they will work on ?86). This is because currently on ?86 the memory layout
> is as follows:

But your patch is enabling randomization for x86_64, because CONFIG_X86
includes both 32 and 64 bit archs.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/