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From: Ingo Molnar <mingo@elte.hu>
To: Avi Kivity <avi@qumranet.com>
Cc: Andrew Morton <akpm@osdl.org>, Andi Kleen <ak@suse.de>,
	linux-kernel@vger.kernel.org, Sam Ravnborg <sam@ravnborg.org>
Subject: Re: [PATCH] Make LIST_POISON less deadly (v3)
Date: Tue, 20 May 2008 13:55:01 +0200	[thread overview]
Message-ID: <20080520115501.GA6045@elte.hu> (raw)
In-Reply-To: <1211283565-30671-1-git-send-email-avi@qumranet.com>


* Avi Kivity <avi@qumranet.com> wrote:

> The list macros use LIST_POISON1 and LIST_POISON2 as undereferencable 
> pointers in order to trap erronous use of freed list_heads.  
> Unfortunately userspace can arrange for those pointers to actually be 
> dereferencable, potentially turning an oops to an expolit.
> 
> To avoid this allow architectures (currently x86_64 only) to override 
> the default values for these pointers with truly-undereferncable 
> values. This is easy on x86_64 as the virtual address space is large 
> and contains unmapped ranges.

looks good - thanks Avi - i've added your patch to the -tip tree. I have 
opened a separate topic for it: tip/safe-poison-pointers. (because it 
affects other architectures as well)

	Ingo

  reply	other threads:[~2008-05-20 11:55 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-05-20 11:39 [PATCH] Make LIST_POISON less deadly (v3) Avi Kivity
2008-05-20 11:55 ` Ingo Molnar [this message]
2008-05-20 15:15 ` Andi Kleen
2008-05-20 15:17   ` Avi Kivity

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