crypto: xcbc - Fix alignment calculation of xcbc_tfm_ctx

The alignment calculation of xcbc_tfm_ctx uses alg->cra_alignmask
and not alg->cra_alignmask + 1 as it should. This led to frequent
crashes during the selftest of xcbc(aes-asm) on x86_64
machines. This patch fixes this. Also we use the alignmask
of xcbc and not the alignmask of the underlying algorithm
for the alignmnent calculation in xcbc_create now.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 5 insertions, 3 deletions

diff --git a/crypto/xcbc.c b/crypto/xcbc.c
index 1e30b31f33c6..bb7b67fba349 100644
--- a/crypto/xcbc.c
+++ b/crypto/xcbc.c
@@ -199,6 +199,7 @@ static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb)
 {
         struct shash_instance *inst;
         struct crypto_alg *alg;
+        unsigned long alignmask;
         int err;
 
         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
@@ -228,19 +229,20 @@ static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb)
         if (err)
                 goto out_free_inst;
 
+        alignmask = alg->cra_alignmask | 3;
+        inst->alg.base.cra_alignmask = alignmask;
         inst->alg.base.cra_priority = alg->cra_priority;
         inst->alg.base.cra_blocksize = alg->cra_blocksize;
-        inst->alg.base.cra_alignmask = alg->cra_alignmask | 3;
 
         inst->alg.digestsize = alg->cra_blocksize;
         inst->alg.descsize = ALIGN(sizeof(struct xcbc_desc_ctx),
                                    crypto_tfm_ctx_alignment()) +
-                             (alg->cra_alignmask &
+                             (alignmask &
                               ~(crypto_tfm_ctx_alignment() - 1)) +
                              alg->cra_blocksize * 2;
 
         inst->alg.base.cra_ctxsize = ALIGN(sizeof(struct xcbc_tfm_ctx),
-                                           alg->cra_alignmask) +
+                                           alignmask + 1) +
                                      alg->cra_blocksize * 2;
         inst->alg.base.cra_init = xcbc_init_tfm;
         inst->alg.base.cra_exit = xcbc_exit_tfm;