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Date:   Mon, 8 Jul 2019 08:27:22 +0200 (CEST)
From:   Julia Lawall <julia.lawall@lip6.fr>
To:     Wen Yang <wen.yang99@zte.com.cn>
cc:     linux-kernel@vger.kernel.org, xue.zhihong@zte.com.cn,
        wang.yi59@zte.com.cn, cheng.shengyu@zte.com.cn,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Thomas Gleixner <tglx@linutronix.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Allison Randal <allison@lohutok.net>,
        Armijn Hemel <armijn@tjaldur.nl>,
        Julia Lawall <Julia.Lawall@lip6.fr>,
        linux-crypto@vger.kernel.org
Subject: Re: [PATCH] crypto: crypto4xx: fix a potential double free in
 ppc4xx_trng_probe
In-Reply-To: <1562566745-7447-2-git-send-email-wen.yang99@zte.com.cn>
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References: <1562566745-7447-1-git-send-email-wen.yang99@zte.com.cn> <1562566745-7447-2-git-send-email-wen.yang99@zte.com.cn>
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On Mon, 8 Jul 2019, Wen Yang wrote:

> There is a possible double free issue in ppc4xx_trng_probe():
>
> 85:	dev->trng_base = of_iomap(trng, 0);
> 86:	of_node_put(trng);          ---> released here
> 87:	if (!dev->trng_base)
> 88:		goto err_out;
> ...
> 110:	ierr_out:
> 111:		of_node_put(trng);  ---> double released here
> ...
>
> This issue was detected by using the Coccinelle software.
> We fix it by removing the unnecessary of_node_put().
>
> Fixes: 5343e674f32 ("crypto4xx: integrate ppc4xx-rng into crypto4xx")
> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Allison Randal <allison@lohutok.net>
> Cc: Armijn Hemel <armijn@tjaldur.nl>
> Cc: Julia Lawall <Julia.Lawall@lip6.fr>
> Cc: linux-crypto@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org

Acked-by: Julia Lawall <julia.lawall@lip6.fr>


> ---
>  drivers/crypto/amcc/crypto4xx_trng.c | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/drivers/crypto/amcc/crypto4xx_trng.c b/drivers/crypto/amcc/crypto4xx_trng.c
> index 02a6bed3..f10a87e 100644
> --- a/drivers/crypto/amcc/crypto4xx_trng.c
> +++ b/drivers/crypto/amcc/crypto4xx_trng.c
> @@ -108,7 +108,6 @@ void ppc4xx_trng_probe(struct crypto4xx_core_device *core_dev)
>  	return;
>
>  err_out:
> -	of_node_put(trng);
>  	iounmap(dev->trng_base);
>  	kfree(rng);
>  	dev->trng_base = NULL;
> --
> 2.9.5
>
>