On Mon, 2020-04-13 at 17:15 -0400, Waiman Long wrote:
> Since kfree_sensitive() will do an implicit memzero_explicit(), there
> is no need to call memzero_explicit() before it. Eliminate those
> memzero_explicit() and simplify the call sites.
2 bits of trivia:
> diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
> b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
[]
> @@ -391,10 +388,7 @@ int sun8i_ce_aes_setkey(struct crypto_skcipher *tfm,
> const u8 *key,
> dev_dbg(ce->dev, "ERROR: Invalid keylen %u\n", keylen);
> return -EINVAL;
> }
> - if (op->key) {
> - memzero_explicit(op->key, op->keylen);
> - kfree(op->key);
> - }
> + kfree_sensitive(op->key);
> op->keylen = keylen;
> op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
> if (!op->key)
It might be a defect to set op->keylen before the kmemdup succeeds.
> @@ -416,10 +410,7 @@ int sun8i_ce_des3_setkey(struct crypto_skcipher *tfm,
> const u8 *key,
> if (err)
> return err;
>
> - if (op->key) {
> - memzero_explicit(op->key, op->keylen);
> - kfree(op->key);
> - }
> + free_sensitive(op->key, op->keylen);
Why not kfree_sensitive(op->key) ?
