On Mon, Aug 02, 2010 at 02:45:37PM +0200, Szilveszter Ördög wrote:
> If a scatterwalk chain contains an entry with an unaligned offset then
> hash_walk_next() will cut off the next step at the next alignment point.
> 
> However, if the entry ends before the next alignment point then we will want 
> to
> process more data than it is available.
> 
> Fix this by checking whether the next aligment point is before the end of the
> current entry.
> ---
>  crypto/ahash.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/crypto/ahash.c b/crypto/ahash.c
> index b8c59b8..f669822 100644
> --- a/crypto/ahash.c
> +++ b/crypto/ahash.c
> @@ -47,8 +47,11 @@ static int hash_walk_next(struct crypto_hash_walk *walk)
>       walk->data = crypto_kmap(walk->pg, 0);
>       walk->data += offset;
> 
> -     if (offset & alignmask)
> -             nbytes = alignmask + 1 - (offset & alignmask);
> +     if (offset & alignmask) {
> +             unsigned int unaligned = alignmask + 1 - (offset & alignmask);
> +             if (nbytes > unaligned)
> +                     nbytes = unaligned;
> +     }
> 
>       walk->entrylen -= nbytes;
>       return nbytes;

The patch looks OK to me.  Dave, what do you think?

But you forgot to attach a Signed-off-by line.  Please resend
with one attached.

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