oss-security - Re: http://www.securityfocus.com/bid/33672/info kernel issue

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Date: Thu, 12 Feb 2009 21:22:59 +0100
From: Marcus Meissner <meissner@...e.de>
To: oss-security@...ts.openwall.com
Subject: Re: http://www.securityfocus.com/bid/33672/info kernel issue

On Thu, Feb 12, 2009 at 08:05:27PM +0000, Mark J Cox wrote:
> >http://www.securityfocus.com/bid/33672/ seems to be this commit:
> >http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.28.y.git;a=commit;h=8255fc826e58c0a59711029e01db9fcdc06ba211
> >Not sure if its exploitable though.
> 
> BTW that BID list of affected kernels isn't correct; the multibyte stuff 
> wasn't in <=2.6.18 at least.
> 
> I didn't check exactly where since it doesn't affect RHEL and didn't look 
> into the issue any further -- but on first glance it seemed like you'd 
> have to be a console user and display/select some carefully chosen 
> characters in order to do the overflow; so it's probably a 'local attacker 
> at keyboard' flaw?

We backported Unicode stuff to SLES 10 I just see, but yes, 2.6.18 then.

Yes, console user only. And you can overflow 2 bytes over the end of kmalloced
space, not sure how much you can do with this.

ciao, Marcus

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