[Users] rowhammer exploit

[Solar Designer]

On Tue, Mar 10, 2015 at 11:40:03PM +0100, Carl-Daniel Hailfinger wrote:
> On 10.03.2015 21:32, Solar Designer wrote:
> > On Tue, Mar 10, 2015 at 02:35:41PM +0100, lst_hoe02 at kwsoft.de wrote:
> >> Zitat von Benjamin Henrion <zoobab at gmail.com>:
> >>> Could this be used to gain HN root access from a container:
> >>>
> >>> http://googleprojectzero.blogspot.be/2015/03/exploiting-dram-rowhammer-bug-to-gain.html?m=1
> >>>
> >>> best,
> >> As i understand this is a hardware defect, so yes it would be  
> >> exploitable within any OS which does not explicit prevent the usage  
> >> pattern of RAM.
> > Yes, but patching the Linux kernel to restrict access to
> > /proc/self/pagemap may mitigate the currently described attack.  This is
> > something the OpenVZ project may do.
> 
> Wouldn't that still leave the way to attack via hugepages which makes
> /proc/self/pagemap partially unneeded?

This mitigation would certainly be far from perfect, and would not
provide any sort of guarantee, but it's whatever we can have cheaply.

Alexander