Bug 92527

Summary:	Information disclosure with HyperThreading (CAN-2005-0109)
Product:	Gentoo Security	Reporter:	kfm <kfm>
Component:	Kernel	Assignee:	Gentoo Security <security>
Status:	RESOLVED CANTFIX
Severity:	trivial
Priority:	High
Version:	unspecified
Hardware:	All
OS:	All
URL:	http://www.daemonology.net/hyperthreading-considered-harmful/
Whiteboard:
Package list:		Runtime testing required:	---

Description kfm 2005-05-13 12:30:26 UTC

Colin Percival (FreeBSD committer and security team member) has claimed to have discovered a flaw potentially affecting a broad array of operating systems that support the use of Intel's HyperThreading technology. He claims that "when running on processors supporting Hyper-Threading Technology, it is possible for a malicious thread to monitor the execution of another thread."

FreeBSD have published an advisory. Here's a short list of links that reference this topic:

http://www.daemonology.net/hyperthreading-considered-harmful/
ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-05:09.htt.asc
http://kerneltrap.org/node/5103

Furthermore, he has now apparently written a paper which presumably demonstrates the exact nature of a possible exploit:

http://www.daemonology.net/papers/htt.pdf

Comment 1 kfm 2005-05-13 12:40:02 UTC

It's under review for the CVE list also (whether Linux is affected still seems unclear): http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-0109

Comment 2 kfm 2005-05-13 12:54:32 UTC

One more thing; a discussion is underway on the LKML: http://article.gmane.org/gmane.linux.kernel/302424 (seems to be some disagreement as to whether it's really an issue from the point of view of the kernel and, of course, whether it's a big deal).

Comment 3 kfm 2005-06-02 06:51:19 UTC

For the benefit of any watchers on this, here's some further discussion of the
matter:

http://kerneltrap.org/node/5197

Also, Con Kolivas posted a concept patch to the LKML demonstrating a "sample
fix". Here's the (interesting) thread:

http://article.gmane.org/gmane.linux.kernel/306979

Comment 4 Tim Yamin (RETIRED) gentoo-dev

2005-06-11 05:30:24 UTC

Still waiting for upstream to decide, adding to status...

Comment 5 Tim Yamin (RETIRED) gentoo-dev

2005-12-23 17:37:09 UTC

I don't think upstream is able or planning to do anything about this, so closing as CANTFIX.