Re: [PATCH v2 3/6] staging: rtl8188eu: use safe iterator in expire_timeout_chk

[Guenter Roeck]

On Mon, May 17, 2021 at 10:18:23PM +0200, Martin Kaiser wrote:
> In the first loop in expire_timeout_chk, we may call rtw_free_stainfo and
> remove an entry from auth_list.
> 
> In the second loop, we may call list_del_init on our list.
> 
> Use list_for_each_entry_safe for both loops.
> 
> Fixes: 23017c8842d2 ("staging: rtl8188eu: Use list iterators and helpers")
> Signed-off-by: Martin Kaiser <martin@xxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
> v2:
>  - use list_for_each_entry_safe
>  - update both loops (I forgot the 2nd loop in v1)
> 
>  drivers/staging/rtl8188eu/core/rtw_ap.c | 12 ++++--------
>  1 file changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/staging/rtl8188eu/core/rtw_ap.c b/drivers/staging/rtl8188eu/core/rtw_ap.c
> index ca9a321c4921..6d7c96f1aa42 100644
> --- a/drivers/staging/rtl8188eu/core/rtw_ap.c
> +++ b/drivers/staging/rtl8188eu/core/rtw_ap.c
> @@ -164,9 +164,9 @@ static u8 chk_sta_is_alive(struct sta_info *psta)
>  
>  void expire_timeout_chk(struct adapter *padapter)
>  {
> -	struct list_head *phead, *plist;
> +	struct list_head *phead;
>  	u8 updated = 0;
> -	struct sta_info *psta = NULL;
> +	struct sta_info *psta, *temp;
>  	struct sta_priv *pstapriv = &padapter->stapriv;
>  	u8 chk_alive_num = 0;
>  	char chk_alive_list[NUM_STA];
> @@ -176,9 +176,7 @@ void expire_timeout_chk(struct adapter *padapter)
>  
>  	phead = &pstapriv->auth_list;
>  	/* check auth_queue */
> -	list_for_each(plist, phead) {
> -		psta = list_entry(plist, struct sta_info, auth_list);
> -
> +	list_for_each_entry_safe(psta, temp, phead, auth_list) {
>  		if (psta->expire_to > 0) {
>  			psta->expire_to--;
>  			if (psta->expire_to == 0) {
> @@ -206,9 +204,7 @@ void expire_timeout_chk(struct adapter *padapter)
>  
>  	phead = &pstapriv->asoc_list;
>  	/* check asoc_queue */
> -	list_for_each(plist, phead) {
> -		psta = list_entry(plist, struct sta_info, asoc_list);
> -
> +	list_for_each_entry_safe(psta, temp, phead, asoc_list) {
>  		if (chk_sta_is_alive(psta) || !psta->expire_to) {
>  			psta->expire_to = pstapriv->expire_to;
>  			psta->keep_alive_trycnt = 0;
> -- 
> 2.20.1
>