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From:   Wen Yang <wen.yang99@zte.com.cn>
To:     linux-kernel@vger.kernel.org
Cc:     xue.zhihong@zte.com.cn, wang.yi59@zte.com.cn,
        cheng.shengyu@zte.com.cn, Wen Yang <wen.yang99@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: [PATCH] crypto: crypto4xx: fix a potential double free in ppc4xx_trng_probe
Date:   Mon, 8 Jul 2019 14:19:03 +0800
Message-Id: <1562566745-7447-2-git-send-email-wen.yang99@zte.com.cn>
In-Reply-To: <1562566745-7447-1-git-send-email-wen.yang99@zte.com.cn>
References: <1562566745-7447-1-git-send-email-wen.yang99@zte.com.cn>
Sender: linux-crypto-owner@vger.kernel.org
Precedence: bulk

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
---
 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