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Message-ID: <d5cde9b6-5f20-4a10-91b1-037887ec79c2@embeddedor.com>
Date: Fri, 19 Jan 2024 11:48:13 -0600
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Subject: Re: [PATCH] staging: rtl8723bs: Use kcalloc() instead of kzalloc()
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To: Erick Archer <erick.archer@gmx.com>,
 Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
 Franziska Naepelt <franziska.naepelt@googlemail.com>,
 Hans de Goede <hdegoede@redhat.com>, Johannes Berg
 <johannes.berg@intel.com>, Jeff Johnson <quic_jjohnson@quicinc.com>,
 Aloka Dixit <quic_alokad@quicinc.com>,
 "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org,
 linux-hardening@vger.kernel.org
References: <20240119173900.11035-1-erick.archer@gmx.com>
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20240119173900.11035-1-erick.archer@gmx.com>
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On 1/19/24 11:39, 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
> count * size 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/staging/rtl8723bs/os_dep/ioctl_cfg80211.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> index 1ff763c10064..65a450fcdce7 100644
> --- a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> +++ b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> @@ -1259,8 +1259,7 @@ static int cfg80211_rtw_scan(struct wiphy *wiphy
>   		goto check_need_indicate_scan_done;
>   	}
> 
> -	ssid = kzalloc(RTW_SSID_SCAN_AMOUNT * sizeof(struct ndis_802_11_ssid),
> -		       GFP_KERNEL);
> +	ssid = kcalloc(RTW_SSID_SCAN_AMOUNT, sizeof(*ssid), GFP_KERNEL);
>   	if (!ssid) {
>   		ret = -ENOMEM;
>   		goto check_need_indicate_scan_done;
> --
> 2.25.1
> 
>