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Message-ID: <cb313841-4540-419a-bb89-5ae806df12b7@embeddedor.com>
Date: Mon, 22 Jan 2024 11:53:45 -0600
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Subject: Re: [PATCH] crypto: sun8i-ce - Use kcalloc() instead of kzalloc()
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To: Erick Archer <erick.archer@gmx.com>,
 Corentin Labbe <clabbe.montjoie@gmail.com>,
 Herbert Xu <herbert@gondor.apana.org.au>,
 "David S. Miller" <davem@davemloft.net>, Chen-Yu Tsai <wens@csie.org>,
 Jernej Skrabec <jernej.skrabec@gmail.com>,
 Samuel Holland <samuel@sholland.org>, Jonathan Corbet <corbet@lwn.net>,
 "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
 linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org,
 linux-hardening@vger.kernel.org
References: <20240121153407.8348-1-erick.archer@gmx.com>
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20240121153407.8348-1-erick.archer@gmx.com>
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On 1/21/24 09:34, Erick Archer wrote:
> As noted in the "Deprecated Interfaces, Language Features, Attributes,
> and Conventions" documentation [1], size calculations (especially
> multiplication) should not be performed in memory allocator (or similar)
> function arguments due to the risk of them overflowing. This could lead
> to values wrapping around and a smaller allocation being made than the
> caller was expecting. Using those allocations could lead to linear
> overflows of heap memory and other misbehaviors.
> 
> So, use the purpose specific kcalloc() function instead of the argument
> size * count in the kzalloc() function.
> 
> Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
> Link: https://github.com/KSPP/linux/issues/162
> Signed-off-by: Erick Archer <erick.archer@gmx.com>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks!
-- 
Gustavo

> ---
>   drivers/crypto/allwinner/sun8i-ce/sun8i-ce-hash.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-hash.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-hash.c
> index d358334e5981..ee2a28c906ed 100644
> --- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-hash.c
> +++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-hash.c
> @@ -362,7 +362,7 @@ int sun8i_ce_hash_run(struct crypto_engine *engine, void *breq)
>   		digestsize = SHA512_DIGEST_SIZE;
> 
>   	/* the padding could be up to two block. */
> -	buf = kzalloc(bs * 2, GFP_KERNEL | GFP_DMA);
> +	buf = kcalloc(2, bs, GFP_KERNEL | GFP_DMA);
>   	if (!buf) {
>   		err = -ENOMEM;
>   		goto theend;
> --
> 2.25.1
>