How much/what hardware does the rowhammer DRAM bug affects?

Georgi Guninski guninski at guninski.com
Fri Sep 18 00:03:42 PDT 2015


On Fri, Sep 18, 2015 at 06:54:58AM +0000, jim bell wrote:
>   From: Georgi Guninski <guninski at guninski.com>
> 
> On Wed, Sep 16, 2015 at 11:46:26PM -0400, grarpamp wrote:
> 
> >http://users.ece.cmu.edu/~omutlu/pub/dram-row-hammer_kim_talk_isca14.pdf
> >p. 32 of the PDF:
> >.– Simple ECC (e.g., SECDED) cannot prevent all errors
> >From wikipedia:  Tests show that simple ECC solutions, providing
> >single-error correction and double-error detection (SECDED)
> >capabilities, are not able to correct or detect all observed
> >disturbance errors because some of them include more than two flipped
> >bits per memory word.[1]:8[11]:32
> >https://en.wikipedia.org/wiki/Row_hammer#cite_ref-isca14-talk_11-0
> 
> But all single-bit and triple-bit errors are detectable by parity, and so are all double-bit errors using ECC.    https://en.wikipedia.org/wiki/Dynamic_random-access_memory#Errors%5Fand%5Ferror%5Fcorrection 
> 
> Jim Bell  

AFAICT Rowhammer (non-weaponized) publicly appeared in:
http://users.ece.cmu.edu/~yoonguk/papers/kim-isca14.pdf

Flipping Bits in Memory Without Accessing Them:
An Experimental Study of DRAM Disturbance Errors
(from 2014)

On p. 8:
Therefore, we conclude that SECDED is not failsafe against disturbance
errors.
Table 5. Uncorrectable multi-bit errors (in bold)

Consider publishing your claim as counterexample to the paper
(possibly on arxiv.org).





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