Re: [PATCH RFC] mm: protect suid binaries against rowhammer with copy-on-read mappings

[Konstantin Khlebnikov <khlebnikov@yandex-team.ru>]

On 19.03.2015 16:04, Vlastimil Babka wrote:
> On 03/18/2015 12:41 PM, Konstantin Khlebnikov wrote:
>> On 18.03.2015 12:57, Kirill A. Shutemov wrote:
>>>
>>> I don't think it worth it. The only right way to fix the problem is ECC
>>> memory.
>>>
>>
>> ECC seems good protection until somebody figure out how to break it too.
>
> I doubt that kind of attitude can get us very far. If we can't trust the
> hardware, we lose sooner or later.
>

Obviously ECC was designed for protecting against cosmic rays which 
flips several bits. If attacker modifies whole cacheline he can chose
value which have the same ECC. I hope next generation of DRAM (or PRAM)
wouldn't be affected.

Software solution is possible: we can put untrusted applications into
special ghetto memory zone. This is relatively easy for virtual 
machines. And it seems might work for normal tasks too (page-cache
pages should be doubled or handled in the way similar to copy-on-read
from that patch).

-- 
Konstantin

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>