Subject: Re: [PATCH RFC v4 net-next 01/26] net: filter: add "load 64-bit immediate" eBPF instruction

From: "H. Peter Anvin" <[email-masked]>
Date: Wed, 13 Aug 2014 14:27:36 -0700

On 08/13/2014 02:23 PM, Andy Lutomirski wrote:
> On Wed, Aug 13, 2014 at 2:21 PM, H. Peter Anvin <[email-masked]> wrote:
>> One thing about this that may be a serious concern: allowing the user to
>> control 8 contiguous bytes of kernel memory may be a security hazard.
> 
> I'm confused.  What kind of memory?  I can control a lot more than 8
> bytes of stack very easily.
> 
> Or are you concerned about 8 contiguous bytes of *executable* memory?
> 

Yes.  Useful for some kinds of ROP custom gadgets.

	-hpa