crypto: api - Fix zeroing on free

Geert Uytterhoeven pointed out that we're not zeroing all the
memory when freeing a transform.  This patch fixes it by calling
ksize to ensure that we zero everything in sight.

Reported-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 10 insertions, 10 deletions

diff --git a/crypto/api.c b/crypto/api.c
index 9975a7bd246c..efe77df6863f 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -557,34 +557,34 @@ err:
         return ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
- 
+
 /*
- *      crypto_free_tfm - Free crypto transform
+ *      crypto_destroy_tfm - Free crypto transform
+ *      @mem: Start of tfm slab
  *      @tfm: Transform to free
  *
- *      crypto_free_tfm() frees up the transform and any associated resources,
+ *      This function frees up the transform and any associated resources,
  *      then drops the refcount on the associated algorithm.
  */
-void crypto_free_tfm(struct crypto_tfm *tfm)
+void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
 {
         struct crypto_alg *alg;
         int size;
 
-        if (unlikely(!tfm))
+        if (unlikely(!mem))
                 return;
 
         alg = tfm->__crt_alg;
-        size = sizeof(*tfm) + alg->cra_ctxsize;
+        size = ksize(mem);
 
         if (!tfm->exit && alg->cra_exit)
                 alg->cra_exit(tfm);
         crypto_exit_ops(tfm);
         crypto_mod_put(alg);
-        memset(tfm, 0, size);
-        kfree(tfm);
+        memset(mem, 0, size);
+        kfree(mem);
 }
-
-EXPORT_SYMBOL_GPL(crypto_free_tfm);
+EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
 
 int crypto_has_alg(const char *name, u32 type, u32 mask)
 {