Re: Needed for the release

[jhd <jan.h.d@swipnet.se>]

11 jun 2005 kl. 01.34 skrev David Kastrup:

> Richard Stallman <rms@gnu.org> writes:
>
>
>> What I remember is that Red Hat enables a feature in Linux that (I
>> believe) uses the address space differently.  unexelf.c doesn't  
>> handle
>> it right.
>>
>> I don't remember the name of the feature, but I'm sure other people
>> on this list remember the name.
>>
>
> exec_shield is one such feature, and newer kernels use something like,
> uh, /proc/sys/vm/randomize_... (I don't remember the particular name
> right now and don't have a Fedora active).  The latter loaded
> executables' memory segments into randomized locations to make buffer
> overflow attacks less predictable.
>
> exec_shield could be gotten around with using
> setarch i386 make
> and configure does that already IIRC.  But the address space
> randomization was prohibiting the dumping even with the setarch
> command.

There is some info in etc/PROBLEMS, and some information here:

http://www.redhat.com/f/pdf/rhel/WHP0006US_Execshield.pdf
http://people.redhat.com/drepper/nonselsec.pdf

And if you search for Exec-shield here:
http://www.redhat.com/docs/manuals/enterprise/RHEL-3-Manual/release- 
notes/as-x86/RELEASE-NOTES-U3-x86-en.html


They don't describe the new randomizing features though.

     Jan D.