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Message-ID: <9294bb03-8c80-47d3-a2d7-8108392ec5d9@embeddedor.com>
Date: Fri, 19 Jan 2024 11:44:22 -0600
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Subject: Re: [PATCH] wifi: iwlegacy: Use kcalloc() instead of kzalloc()
To: Erick Archer <erick.archer@gmx.com>, Stanislaw Gruszka <stf_xl@wp.pl>,
 Kalle Valo <kvalo@kernel.org>, "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-hardening@vger.kernel.org
References: <20240119171655.7740-1-erick.archer@gmx.com>
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From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20240119171655.7740-1-erick.archer@gmx.com>
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On 1/19/24 11:16, 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 kcalloc() function instead of the argument
> size * count in the kzalloc() function.
> 
> Also, it is preferred to use sizeof(*pointer) instead of sizeof(type)
> due to the type of the variable can change and one needs not change the
> former (unlike the latter).
> 
> 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/net/wireless/intel/iwlegacy/common.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c
> index 17570d62c896..9d33a66a49b5 100644
> --- a/drivers/net/wireless/intel/iwlegacy/common.c
> +++ b/drivers/net/wireless/intel/iwlegacy/common.c
> @@ -3438,9 +3438,7 @@ il_init_geos(struct il_priv *il)
>   	if (!channels)
>   		return -ENOMEM;
> 
> -	rates =
> -	    kzalloc((sizeof(struct ieee80211_rate) * RATE_COUNT_LEGACY),
> -		    GFP_KERNEL);
> +	rates = kcalloc(RATE_COUNT_LEGACY, sizeof(*rates), GFP_KERNEL);
>   	if (!rates) {
>   		kfree(channels);
>   		return -ENOMEM;
> --
> 2.25.1
> 
>