Ethical Hacking

Learn to find vulnerabilities before the bad guys do! Gain real world hands on hacking experience in our state of the art hacking lab. Course designed and taught by expert instructors with years of penetration testing experience. 12 student maximum in every class. Certification attempt included in every package.
Computer Forensics Training at InfoSec Institute

Gain the in-demand skills of a certified computer examiner, learn to recover trace data left behind by fraud, theft, and cybercrime perpetrators. Discover the source of computer crime and abuse at your organization so that it never happens again. All of our class sizes are guaranteed to be 12 students or less to facilitate one-on-one interaction with one of our expert instructors.




Network Security FullDisclosure
[Top] [All Lists]

Re: [Full-disclosure] Intel Core 2 CPUs are buggy. Patch your cpus :D

Subject: Re: [Full-disclosure] Intel Core 2 CPUs are buggy. Patch your cpus :D
Date: Thu, 28 Jun 2007 11:55:39 -0700
  - Basically the MMU simply does not operate as specified/implimented
    in previous generations of x86 hardware.  It is not just buggy, but
    Intel has gone further and defined "new ways to handle page tables"
    (see page 58).

I'm not sure about this - I understood it to mean that if you touch a
table, you have to invalidate the TLB that corresponds to its linear
address.  This was always how Intel CPUs behaved, even the old ones.
What changed?

  - Some of these bugs are along the lines of "buffer overflow"; where
    a write-protect or non-execute bit for a page table entry is ignored.

Same thing here - altering tables without flushing the TLBs will result in
cached data being used instead.  Intel is documenting it very well now, but
it's not new behaviour.

    Others are floating point instruction non-coherencies, or memory
    corruptions -- outside of the range of permitted writing for the
    process -- running common instruction sequences.

The FPU memory corruption is old behaviour, too.

Certainly, there are some scary things in the list, but many of them are
behaviours that are being documented for the first time, yet they exist
in CPUs since even the 486, for example.

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

<Prev in Thread] Current Thread [Next in Thread>