Date:   Thu, 23 Feb 2023 14:00:39 +0800
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     Li kunyu <kunyu@nfschina.com>,
        Linus Walleij <linus.walleij@linaro.org>
Cc:     davem@davemloft.net, mcoquelin.stm32@gmail.com,
        linux-crypto@vger.kernel.org,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] stm32: stm32-hash: Add kmalloc_array allocation check
Message-ID: <Y/cBB+q0Ono9j2Jy@gondor.apana.org.au>
References: <20230224215019.3687-1-kunyu@nfschina.com>
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On Sat, Feb 25, 2023 at 05:50:19AM +0800, Li kunyu wrote:
> If rctx->hw_context allocation of the context pointer failed. Returning
> -ENOMEM and assigning NULL to the out pointer should improve the
> robustness of the function.
> 
> Signed-off-by: Li kunyu <kunyu@nfschina.com>
> ---
>  drivers/crypto/stm32/stm32-hash.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/crypto/stm32/stm32-hash.c b/drivers/crypto/stm32/stm32-hash.c
> index d33006d43f76..18e79f62be96 100644
> --- a/drivers/crypto/stm32/stm32-hash.c
> +++ b/drivers/crypto/stm32/stm32-hash.c
> @@ -970,6 +970,10 @@ static int stm32_hash_export(struct ahash_request *req, void *out)
>  	rctx->hw_context = kmalloc_array(3 + HASH_CSR_REGISTER_NUMBER,
>  					 sizeof(u32),
>  					 GFP_KERNEL);
> +	if (rctx->hw_context == NULL) {
> +		out = NULL;
> +		return -ENOMEM;
> +	}
>  
>  	preg = rctx->hw_context;

Shouldn't we free the hw_context at the end of the function?

Why does it even need to be stored in rctx in the first place?

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt