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Subject: Re: [PATCH] crypto: sun8i-ce: rename kfree() to kfree_sensitive()
To:     Yang Li <yang.lee@linux.alibaba.com>, clabbe.montjoie@gmail.com
Cc:     herbert@gondor.apana.org.au, davem@davemloft.net,
        mripard@kernel.org, wens@csie.org, jernej.skrabec@siol.net,
        linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
References: <1614594641-35606-1-git-send-email-yang.lee@linux.alibaba.com>
From:   Christophe Leroy <christophe.leroy@csgroup.eu>
Message-ID: <4f448ec8-3694-b918-30eb-641d473c85ff@csgroup.eu>
Date:   Mon, 1 Mar 2021 11:35:41 +0100
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Le 01/03/2021 à 11:30, Yang Li a écrit :
> Rename kfree() to kfree_sensitive() to  make the intention of the API
> more explicit.

As far as I understand, you are not renaming kfree() to kfree_sensitive().

You are making a change to use kfree_sensitive() instead of using kfree().

Christophe

> 
> fixed the following coccicheck:
> ./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:30:16-17: WARNING
> opportunity for kfree_sensitive/kvfree_sensitive (memset at line 29)
> ./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:42:16-17: WARNING
> opportunity for kfree_sensitive/kvfree_sensitive (memset at line 41)
> ./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:161:8-9: WARNING
> opportunity for kfree_sensitive/kvfree_sensitive (memset at line 109)
> 
> Reported-by: Abaci Robot <abaci@linux.alibaba.com>
> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
> ---
>   drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
> index cfde9ee..8259d52 100644
> --- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
> +++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
> @@ -27,7 +27,7 @@ void sun8i_ce_prng_exit(struct crypto_tfm *tfm)
>   	struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
>   
>   	memzero_explicit(ctx->seed, ctx->slen);
> -	kfree(ctx->seed);
> +	kfree_sensitive(ctx->seed);
>   	ctx->seed = NULL;
>   	ctx->slen = 0;
>   }
> @@ -39,7 +39,7 @@ int sun8i_ce_prng_seed(struct crypto_rng *tfm, const u8 *seed,
>   
>   	if (ctx->seed && ctx->slen != slen) {
>   		memzero_explicit(ctx->seed, ctx->slen);
> -		kfree(ctx->seed);
> +		kfree_sensitive(ctx->seed);
>   		ctx->slen = 0;
>   		ctx->seed = NULL;
>   	}
> @@ -158,7 +158,7 @@ int sun8i_ce_prng_generate(struct crypto_rng *tfm, const u8 *src,
>   	}
>   	memzero_explicit(d, todo);
>   err_iv:
> -	kfree(d);
> +	kfree_sensitive(d);
>   err_mem:
>   	return err;
>   }
>