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Message-ID: <f82fdbaa-fed4-cbd3-b559-53bdd373b923@amlogic.com>
Date:   Thu, 26 May 2022 13:34:45 +0800
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Subject: Re: [PATCH] mtd: rawnand: meson: Fix a potential double free issue
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To:     Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Kevin Hilman <khilman@baylibre.com>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Yixun Lan <yixun.lan@amlogic.com>,
        Jianxin Pan <jianxin.pan@amlogic.com>
CC:     <linux-kernel@vger.kernel.org>, <kernel-janitors@vger.kernel.org>,
        <linux-mtd@lists.infradead.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-amlogic@lists.infradead.org>
References: <ec15c358b8063f7c50ff4cd628cf0d2e14e43f49.1653064877.git.christophe.jaillet@wanadoo.fr>
From:   Liang Yang <liang.yang@amlogic.com>
In-Reply-To: <ec15c358b8063f7c50ff4cd628cf0d2e14e43f49.1653064877.git.christophe.jaillet@wanadoo.fr>
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Hi Christophe,

On 2022/5/21 0:41, Christophe JAILLET wrote:
> [ EXTERNAL EMAIL ]
> 
> When meson_nfc_nand_chip_cleanup() is called, it will call:
> 	meson_nfc_free_buffer(&meson_chip->nand);
> 	nand_cleanup(&meson_chip->nand);
> 
> nand_cleanup() in turn will call nand_detach() which calls the
> .detach_chip() which is here meson_nand_detach_chip().
> 
> meson_nand_detach_chip() already calls meson_nfc_free_buffer(), so we
> could double free some memory.
> 
> Fix it by removing the unneeded explicit call to meson_nfc_free_buffer().
> 
> Fixes: 8fae856c5350 ("mtd: rawnand: meson: add support for Amlogic NAND flash controller")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> This patch is speculative, so review with care.
> ---
>   drivers/mtd/nand/raw/meson_nand.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> index ac3be92872d0..032180183339 100644
> --- a/drivers/mtd/nand/raw/meson_nand.c
> +++ b/drivers/mtd/nand/raw/meson_nand.c
> @@ -1307,7 +1307,6 @@ static int meson_nfc_nand_chip_cleanup(struct meson_nfc *nfc)
>   		if (ret)
>   			return ret;
>   
> -		meson_nfc_free_buffer(&meson_chip->nand);
>   		nand_cleanup(&meson_chip->nand);
>   		list_del(&meson_chip->node);
>   	}

Acked-by: Liang Yang <liang.yang@amlogic.com>

Thanks,
Liang