From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Date: Wed, 4 Aug 2010 21:48:51 +0800
> 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?
Looks good, thanks Szilveszter:
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
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