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Subject: Re: [PATCH] crypto: hisilicon/hpre - rsa key should not be empty
To:     Herbert Xu <herbert@gondor.apana.org.au>
CC:     <davem@davemloft.net>, <linux-crypto@vger.kernel.org>,
        <xuzaibo@huawei.com>, <wangzhou1@hisilicon.com>,
        <linux-kernel@vger.kernel.org>, <shenyang39@huawei.com>
References: <1616739212-7751-1-git-send-email-yumeng18@huawei.com>
 <20210402071225.GA10423@gondor.apana.org.au>
From:   yumeng <yumeng18@huawei.com>
Message-ID: <7384e015-5514-d6b2-4215-beb1f4701adb@huawei.com>
Date:   Fri, 2 Apr 2021 18:16:16 +0800
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?? 2021/4/2 15:12, Herbert Xu д??:
> On Fri, Mar 26, 2021 at 02:13:32PM +0800, Meng Yu wrote:
>> We should ensure key is not empty before we set key.
>>
>> Signed-off-by: Meng Yu <yumeng18@huawei.com>
>> ---
>>   drivers/crypto/hisilicon/hpre/hpre_crypto.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/crypto/hisilicon/hpre/hpre_crypto.c b/drivers/crypto/hisilicon/hpre/hpre_crypto.c
>> index 53068d2..7cf7d80 100644
>> --- a/drivers/crypto/hisilicon/hpre/hpre_crypto.c
>> +++ b/drivers/crypto/hisilicon/hpre/hpre_crypto.c
>> @@ -1093,6 +1093,9 @@ static int hpre_rsa_setpubkey(struct crypto_akcipher *tfm, const void *key,
>>   	struct hpre_ctx *ctx = akcipher_tfm_ctx(tfm);
>>   	int ret;
>>   
>> +	if (!key || !keylen)
>> +		return -EINVAL;
>> +
>>   	ret = crypto_akcipher_set_pub_key(ctx->rsa.soft_tfm, key, keylen);
> 
> Does this fix a real bug? Wouldn't the soft fallback setkey catch
> this anyhow?
> 

I think it is not a real bug, and soft fallback setkey can always catch 
the error.
But our original intention was to make it don't go to 'xxx_set_pub_key'
when the key is null, and it can return an error earlier.
But maybe it is not good.