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From:   Stephan Mueller <smueller@chronox.de>
To:     Zheng Bin <zhengbin13@huawei.com>
Cc:     herbert@gondor.apana.org.au, davem@davemloft.net,
        linux-crypto@vger.kernel.org
Subject: Re: [PATCH] crypto: drbg - Fix memleak in drbg_prepare_hrng
Date:   Thu, 11 Jun 2020 10:33:58 +0200
Message-ID: <37905178.8f6zGtLfKx@tauon.chronox.de>
In-Reply-To: <20200611083356.88600-1-zhengbin13@huawei.com>
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Am Donnerstag, 11. Juni 2020, 10:33:56 CEST schrieb Zheng Bin:

Hi Zheng,

Thank you for the note, but I think this is handled, albeit differently. 
Search for patch "[PATCH v3] crypto: DRBG - always try to free Jitter RNG 
instance" that is sent to the list (but not yet applied).

Thanks


> drbg_prepare_hrng
>   drbg->jent = crypto_alloc_rng
>   err = add_random_ready_callback
>   default:
>     drbg->random_ready.func = NULL  -->set NULL, if fail
> 
> drbg_uninstantiate
>   if (drbg->random_ready.func)      -->If NULL, will not free drbg->jent
>     crypto_free_rng(drbg->jent)
> 
> Need to free drbg->jent if add_random_ready_callback return fail.
> 
> Fixes: 97f2650e5040 ("crypto: drbg - always seeded with SP800-90B compliant
> noise source") Signed-off-by: Zheng Bin <zhengbin13@huawei.com>
> ---
>  crypto/drbg.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/crypto/drbg.c b/crypto/drbg.c
> index 37526eb8c5d5..a643ab7eac7a 100644
> --- a/crypto/drbg.c
> +++ b/crypto/drbg.c
> @@ -1524,6 +1524,8 @@ static int drbg_prepare_hrng(struct drbg_state *drbg)
>  		/* fall through */
> 
>  	default:
> +		crypto_free_rng(drbg->jent);
> +		drbg->jent = NULL;
>  		drbg->random_ready.func = NULL;
>  		return err;
>  	}
> --
> 2.26.0.106.g9fadedd


Ciao
Stephan