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Message-ID: <2a8afc70-c0d8-2b37-9d49-9a054a30ea4b@gmail.com>
Date:   Thu, 24 Mar 2022 10:04:44 -0700
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Subject: Re: [PATCH v1] soc: bcm: Check for NULL return of devm_kzalloc()
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To:     QintaoShen <unSimple1993@163.com>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>
Cc:     bcm-kernel-feedback-list@broadcom.com, linux-mips@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <1648110940-4684-1-git-send-email-unSimple1993@163.com>
From:   Florian Fainelli <f.fainelli@gmail.com>
In-Reply-To: <1648110940-4684-1-git-send-email-unSimple1993@163.com>
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+Rafal,

On 3/24/22 01:35, QintaoShen wrote:
> As the potential failuer of allocation, devm_kzalloc() may return NULL.

s/failuer/failure/

> Then the 'pd->pmb' and the follow lines of code may bring null pointer dereference.
> 
> Therefore, it is better to check the return value of devm_kzalloc() to avoid this confusion.
> 
> Signed-off-by: QintaoShen <unSimple1993@163.com>

Fixes: 8bcac4011ebe ("soc: bcm: add PM driver for Broadcom's PMB")

> ---
>   drivers/soc/bcm/bcm63xx/bcm-pmb.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/soc/bcm/bcm63xx/bcm-pmb.c b/drivers/soc/bcm/bcm63xx/bcm-pmb.c
> index 7bbe46e..55bf389 100644
> --- a/drivers/soc/bcm/bcm63xx/bcm-pmb.c
> +++ b/drivers/soc/bcm/bcm63xx/bcm-pmb.c
> @@ -311,6 +311,8 @@ static int bcm_pmb_probe(struct platform_device *pdev)
>   
>   	for (e = table; e->name; e++) {
>   		struct bcm_pmb_pm_domain *pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
> +		if (!pd)
> +			return -ENOMEM;

I am of two minds as to what the appropriate behavior could be here, we 
could equally use an:

		if (!pd)
			continue;

or do what you are doing.

>   
>   		pd->pmb = pmb;
>   		pd->data = e;


-- 
Florian