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Subject: Re: [PATCH 3/3] rtlwifi: rtl8192de: fix array size limit in for-loop
To:     Joe Perches <joe@perches.com>, Ping-Ke Shih <pkshih@realtek.com>,
        Kalle Valo <kvalo@codeaurora.org>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org
Cc:     kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20210803144949.79433-1-colin.king@canonical.com>
 <20210803144949.79433-3-colin.king@canonical.com>
 <39b42c868d1aa01bb421733aac32f072dc85e393.camel@perches.com>
From:   Colin Ian King <colin.king@canonical.com>
Message-ID: <3ce51250-bf32-97a6-a7e1-f49b27116907@canonical.com>
Date:   Tue, 3 Aug 2021 19:12:33 +0100
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On 03/08/2021 19:11, Joe Perches wrote:
> On Tue, 2021-08-03 at 15:49 +0100, Colin King wrote:
>> From: Colin Ian King <colin.king@canonical.com>
>>
>> Currently the size of the entire array is being used in a for-loop
>> for the element count. While this works since the elements are u8
>> sized, it is preferred to use ARRAY_SIZE to get the element count
>> of the array.
> []
>> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> []
>> @@ -1366,7 +1366,7 @@ u8 rtl92d_get_rightchnlplace_for_iqk(u8 chnl)
>>  	u8 place = chnl;
>>
>>  	if (chnl > 14) {
>> -		for (place = 14; place < sizeof(channel_all); place++) {
>> +		for (place = 14; place < ARRAY_SIZE(channel_all); place++) {
>>  			if (channel_all[place] == chnl)
>>  				return place - 13;
>>  		}
> 
> Thanks.
> 
> It seems a relatively common copy/paste use in rtlwifi

Urgh. Let's drop patch 3/3 for the moment. I'll send a fix later on, I'm
kinda tied up for the next 24 hours.


> 
> $ git grep -P -n 'for\b.*<\s*sizeof\s*\(\s*\w+\w*\)\s*;' drivers/net/wireless/realtek/rtlwifi/
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:893:               for (place = 14; place < sizeof(channel5g); place++) {
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:1368:              for (place = 14; place < sizeof(channel_all); place++) {
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:2430:      for (i = 0; i < sizeof(channel5g); i++)
> drivers/net/wireless/realtek/rtlwifi/rtl8192ee/phy.c:2781:              for (place = 14; place < sizeof(channel_all); place++) {
> drivers/net/wireless/realtek/rtlwifi/rtl8723be/phy.c:2170:              for (place = 14; place < sizeof(channel_all); place++) {
> drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c:3610:              for (place = 14; place < sizeof(channel_all); place++)
> 
> 
>