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Message-ID: <b75129be-04fc-4818-a9f9-eb35dca4b689@embeddedor.com>
Date: Fri, 19 Jan 2024 12:26:36 -0600
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Subject: Re: [PATCH] pinctrl: pinctrl-zynqmp: Use devm_kcalloc() instead of
 devm_kzalloc()
Content-Language: en-US
To: Erick Archer <erick.archer@gmx.com>,
 Linus Walleij <linus.walleij@linaro.org>, Michal Simek
 <michal.simek@amd.com>, "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
 linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
References: <20240119181909.7079-1-erick.archer@gmx.com>
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20240119181909.7079-1-erick.archer@gmx.com>
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On 1/19/24 12:19, Erick Archer wrote:
> As noted in the "Deprecated Interfaces, Language Features, Attributes,
> and Conventions" documentation [1], size calculations (especially
> multiplication) should not be performed in memory allocator (or similar)
> function arguments due to the risk of them overflowing. This could lead
> to values wrapping around and a smaller allocation being made than the
> caller was expecting. Using those allocations could lead to linear
> overflows of heap memory and other misbehaviors.
> 
> So, use the purpose specific devm_kcalloc() function instead of the
> argument size * count in the devm_kzalloc() function.
> 
> Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
> Link: https://github.com/KSPP/linux/issues/162
> Signed-off-by: Erick Archer <erick.archer@gmx.com>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks!
-- 
Gustavo

> ---
>   drivers/pinctrl/pinctrl-zynqmp.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pinctrl/pinctrl-zynqmp.c b/drivers/pinctrl/pinctrl-zynqmp.c
> index f2be341f73e1..5c46b7d7ebcb 100644
> --- a/drivers/pinctrl/pinctrl-zynqmp.c
> +++ b/drivers/pinctrl/pinctrl-zynqmp.c
> @@ -562,7 +562,7 @@ static int zynqmp_pinctrl_prepare_func_groups(struct device *dev, u32 fid,
>   	const char **fgroups;
>   	int ret, index, i;
> 
> -	fgroups = devm_kzalloc(dev, sizeof(*fgroups) * func->ngroups, GFP_KERNEL);
> +	fgroups = devm_kcalloc(dev, func->ngroups, sizeof(*fgroups), GFP_KERNEL);
>   	if (!fgroups)
>   		return -ENOMEM;
> 
> @@ -754,7 +754,7 @@ static int zynqmp_pinctrl_prepare_function_info(struct device *dev,
>   	if (ret)
>   		return ret;
> 
> -	funcs = devm_kzalloc(dev, sizeof(*funcs) * pctrl->nfuncs, GFP_KERNEL);
> +	funcs = devm_kcalloc(dev, pctrl->nfuncs, sizeof(*funcs), GFP_KERNEL);
>   	if (!funcs)
>   		return -ENOMEM;
> 
> @@ -768,7 +768,7 @@ static int zynqmp_pinctrl_prepare_function_info(struct device *dev,
>   		pctrl->ngroups += funcs[i].ngroups;
>   	}
> 
> -	groups = devm_kzalloc(dev, sizeof(*groups) * pctrl->ngroups, GFP_KERNEL);
> +	groups = devm_kcalloc(dev, pctrl->ngroups, sizeof(*groups), GFP_KERNEL);
>   	if (!groups)
>   		return -ENOMEM;
> 
> @@ -830,7 +830,7 @@ static int zynqmp_pinctrl_prepare_pin_desc(struct device *dev,
>   	if (ret)
>   		return ret;
> 
> -	pins = devm_kzalloc(dev, sizeof(*pins) * *npins, GFP_KERNEL);
> +	pins = devm_kcalloc(dev, *npins, sizeof(*pins), GFP_KERNEL);
>   	if (!pins)
>   		return -ENOMEM;
> 
> --
> 2.25.1
> 
>