Re: [PATCH] crypto: sun8i-ce - use kfree_sensitive()

[Corentin Labbe <clabbe.montjoie@gmail.com>]

On Wed, Aug 26, 2020 at 04:25:37PM +0300, Denis Efremov wrote:
> Use kfree_sensitive() instead of open-coding it.
> 
> Signed-off-by: Denis Efremov <efremov@linux.com>
> ---
>  drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
> index b4d5fea27d20..970084463dbb 100644
> --- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
> +++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
> @@ -367,8 +367,7 @@ void sun8i_ce_cipher_exit(struct crypto_tfm *tfm)
>  	struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
>  
>  	if (op->key) {
> -		memzero_explicit(op->key, op->keylen);
> -		kfree(op->key);
> +		kfree_sensitive(op->key);
>  	}
>  	crypto_free_skcipher(op->fallback_tfm);
>  	pm_runtime_put_sync_suspend(op->ce->dev);
> @@ -392,8 +391,7 @@ int sun8i_ce_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
>  		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);
> @@ -417,8 +415,7 @@ int sun8i_ce_des3_setkey(struct crypto_skcipher *tfm, const u8 *key,
>  		return err;
>  
>  	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);
> -- 
> 2.26.2
> 

Hello

Same problem than amlogic and sun8i-ss.
Please remove if (op->key)

Regards