Re: How to enable/disable security features on mmap() ?

[linux-os (Dick Johnson)]

On Thu, 8 Dec 2005, Arjan van de Ven wrote:

> On Thu, 2005-12-08 at 17:20 +0100, Xavier Bestel wrote:
>> If you only randomize by one or two bytes, the attacker just has to
>> retry once or twice to have his exploit work.
>
> in addition the stack pointer needs to be 16 byte aligned in the first
> place ;)
>

No. The stack-pointer is most efficient on ix86 machines if it is
aligned on an ESP-sized boundary (32 bits). Any DATA allocated on
the stack __should__ be aligned to take any data-type, i.e., 16 bytes
to accommodate floating-point variables.

Cheers,
Dick Johnson
Penguin : Linux version 2.6.13.4 on an i686 machine (5589.55 BogoMips).
Warning : 98.36% of all statistics are fiction.
.

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