lkml.org 
[lkml]   [2014]   [Nov]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: crypto: zeroization of sensitive data in af_alg
On Tue, Nov 11, 2014 at 03:06:32AM +0100, Stephan Mueller wrote:
> Am Montag, 10. November 2014, 22:05:18 schrieb Herbert Xu:
>
> Hi Herbert,
>
> > On Sun, Nov 09, 2014 at 11:33:52PM +0100, Stephan Mueller wrote:
> > > while working on the AF_ALG interface, I saw no active zeroizations of
> > > memory that may hold sensitive data that is maintained outside the kernel
> > > crypto API cipher handles. I think the following memory segments fall
> > > under that
> > > category:
> > Are you talking about temporary data that we generate as part of
> > the processing? If so they should be zeroed by the entity that
> > generates them.
>
> I currently see that the IV buffer (owned by skcipher) and the message digest
> buffer (owned by hash) are not memset(0) before freeing them. I agree that
> both are not really sensitive data. But wouldn't it be prudent to memset(0)
> them nonetheless in the skcipher_sock_destruct and hash_sock_destruct
> functions, respectively?

Yes please submit your patches.

> Apologies, my bad as I did not check get_user_pages_fast well enough. I see
> now that we operate on the pages in user space directly without copy_from_user
> that would imply a kernel-internal copy. Please disregard my comment.

OK.

Thanks,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt


\
 
 \ /
  Last update: 2014-11-11 04:21    [W:0.058 / U:0.116 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site