The cipher code relies on the fact that the block size is a multiple
of the required alignment.  So we should check this at the time of
algorith registration.  We also ensure that the block size is bounded
by the page size.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
        if (alg->cra_alignmask & (alg->cra_alignmask + 1))
                return -EINVAL;
 
-       if (alg->cra_alignmask > PAGE_SIZE)
+       if (alg->cra_alignmask & alg->cra_blocksize)
+               return -EINVAL;
+
+       if (alg->cra_blocksize > PAGE_SIZE)
                return -EINVAL;
        
        down_write(&crypto_alg_sem);