Re: [PATCH 1/1] rtlwifi: always initialize variables given to RT_TRACE()

[Larry Finger]

On 12/10/2017 01:51 PM, Nicolas Iooss wrote:
> In rtl_rx_ampdu_apply(), when rtlpriv->cfg->ops->get_btc_status()
> returns false, RT_TRACE() is called with the values of variables
> reject_agg and agg_size, which have not been initialized.
>
> Always initialize these variables in order to prevent using
> uninitialized values.
>
> This issue has been found with clang. The compiler reported:
>
>      drivers/net/wireless/realtek/rtlwifi/base.c:1665:6: error: variable
>      'agg_size' is used uninitialized whenever 'if' condition is false
>      [-Werror,-Wsometimes-uninitialized]
>              if (rtlpriv->cfg->ops->get_btc_status())
>                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>      drivers/net/wireless/realtek/rtlwifi/base.c:1671:31: note:
>      uninitialized use occurs here
>                       reject_agg, ctrl_agg_size, agg_size);
>                                                  ^~~~~~~~
>
>      drivers/net/wireless/realtek/rtlwifi/base.c:1665:6: error: variable
>      'reject_agg' is used uninitialized whenever 'if' condition
>            is false [-Werror,-Wsometimes-uninitialized]
>              if (rtlpriv->cfg->ops->get_btc_status())
>                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>      drivers/net/wireless/realtek/rtlwifi/base.c:1671:4: note:
>      uninitialized use occurs here
>                       reject_agg, ctrl_agg_size, agg_size);
>                       ^~~~~~~~~~
>
> Fixes: 2635664e6e4a ("rtlwifi: Add rx ampdu cfg for btcoexist.")
> Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@xxxxxxx>

Looks good. Acked-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>

Thanks,

Larry

> ---
>   drivers/net/wireless/realtek/rtlwifi/base.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/realtek/rtlwifi/base.c b/drivers/net/wireless/realtek/rtlwifi/base.c
> index cad2272ae21b..704741d6f495 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/base.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/base.c
> @@ -1726,7 +1726,7 @@ int rtl_tx_agg_oper(struct ieee80211_hw *hw,
>   void rtl_rx_ampdu_apply(struct rtl_priv *rtlpriv)
>   {
>   	struct rtl_btc_ops *btc_ops = rtlpriv->btcoexist.btc_ops;
> -	u8 reject_agg, ctrl_agg_size = 0, agg_size;
> +	u8 reject_agg = 0, ctrl_agg_size = 0, agg_size = 0;
>   
>   	if (rtlpriv->cfg->ops->get_btc_status())
>   		btc_ops->btc_get_ampdu_cfg(rtlpriv, &reject_agg,