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Subject: Re: [PATCH net v4] net: mvpp2: fix possible invalid pointer
 dereference
To:     Jakub Kicinski <kuba@kernel.org>
References: <20221116020617.137247-1-tanghui20@huawei.com>
 <20221116021437.145204-1-tanghui20@huawei.com>
 <20221115202850.7beeea87@kernel.org>
CC:     <davem@davemloft.net>, <edumazet@google.com>, <mw@semihalf.com>,
        <linux@armlinux.org.uk>, <leon@kernel.org>, <andrew@lunn.ch>,
        <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <yusongping@huawei.com>
From:   Hui Tang <tanghui20@huawei.com>
Message-ID: <a061d870-d0ce-a580-636d-600a9a4b006f@huawei.com>
Date:   Wed, 16 Nov 2022 14:13:14 +0800
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On 2022/11/16 12:28, Jakub Kicinski wrote:
> On Wed, 16 Nov 2022 10:14:37 +0800 Hui Tang wrote:
>> It will cause invalid pointer dereference to priv->cm3_base behind,
>> if PTR_ERR(priv->cm3_base) in mvpp2_get_sram().
>>
>> Fixes: a59d354208a7 ("net: mvpp2: enable global flow control")
>> Signed-off-by: Hui Tang <tanghui20@huawei.com>
>
> Please do not repost new versions so often:
>
> https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#tl-dr
>
> do not use --in-reply-to

Thanks for pointing out, but should I resend it with [PATCH net v3]  or [PATCH net v5]?

>> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
>> index d98f7e9a480e..efb582b63640 100644
>> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
>> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
>> @@ -7349,6 +7349,7 @@ static int mvpp2_get_sram(struct platform_device *pdev,
>>  			  struct mvpp2 *priv)
>>  {
>>  	struct resource *res;
>> +	void __iomem *base;
>>
>>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
>>  	if (!res) {
>> @@ -7359,9 +7360,11 @@ static int mvpp2_get_sram(struct platform_device *pdev,
>>  		return 0;
>>  	}
>>
>> -	priv->cm3_base = devm_ioremap_resource(&pdev->dev, res);
>> +	base = devm_ioremap_resource(&pdev->dev, res);
>> +	if (!IS_ERR(base))
>> +		priv->cm3_base = base;
>>
>> -	return PTR_ERR_OR_ZERO(priv->cm3_base);
>> +	return PTR_ERR_OR_ZERO(base);
>
> Use the idiomatic error handling, keep success path un-indented:
>
> 	ptr = function();
> 	if (IS_ERR(ptr))
> 		return PTR_ERR(ptr);
>
> 	priv->bla = ptr;
> 	return 0;
> 	
>
Ok, I will fix it in next version