lkml.org 
[lkml]   [2022]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH alternative 2] block: fix the REQ_OP_SECURE_ERASE handling to not leak erased data
On Fri, 18 Mar 2022 at 10:11, Christoph Hellwig <hch@lst.de> wrote:
>
> On Thu, Mar 17, 2022 at 10:44:01AM +0100, Ulf Hansson wrote:
> > Stating that it can't work is probably not a correct statement.
> > Certainly it can, but it depends on how "secure" (or clever) the
> > implementation of the FTL is in the flash media. I mean, nothing
> > prevents the FTL from doing a real erase on erase block level and
> > simply let the "secure erase" request wait on that operation to be
> > completed.
>
> Well, that assumes it can find all the previous copied of the data.
> Having worked with various higher end SSDs FTLs I know they can't,
> so if an eMMC device could that would very much surpise me given
> the overhead.

An eMMC is no different from an SSD in this regard, so you are most
definitely correct. BTW, I was one of those guys working with FTLs
myself, but it was a long time ago, when NAND/NOR flashes were less
complicated to manage.

Anyway, to really make things work, one would need some additional low
level partitioning - or commands to tag the data for special
purposes. eMMCs do have some support for things like this, but whether
it actually works to serve this particular use case (secure erase), I
really can't tell.

Kind regards
Uffe

\
 
 \ /
  Last update: 2022-03-18 11:37    [W:0.077 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site