Re: [PATCH 3/7] staging: rtl8188eu: use safe iterator in dequeue_xmitframes_to_sleeping_queue()

[Guenter Roeck <linux@roeck-us.net>]

On Mon, Jun 07, 2021 at 09:17:43PM +0300, Dan Carpenter wrote:
> On some code paths the xmitframe_enqueue_for_sleeping_sta() function can
> call list_del_init(&pxmitframe->list) which would lead to a forever loop
> because "pxmitframe" is the list iterator.  Use the _safe version of the
> iterator to prevent this.
> 
> Fixes: 23017c8842d2 ("staging: rtl8188eu: Use list iterators and helpers")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/staging/rtl8188eu/core/rtw_xmit.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/staging/rtl8188eu/core/rtw_xmit.c b/drivers/staging/rtl8188eu/core/rtw_xmit.c
> index dcc29a74612d..f57e41f817ca 100644
> --- a/drivers/staging/rtl8188eu/core/rtw_xmit.c
> +++ b/drivers/staging/rtl8188eu/core/rtw_xmit.c
> @@ -1729,17 +1729,15 @@ int xmitframe_enqueue_for_sleeping_sta(struct adapter *padapter, struct xmit_fra
>  
>  static void dequeue_xmitframes_to_sleeping_queue(struct adapter *padapter, struct sta_info *psta, struct __queue *pframequeue)
>  {
> -	struct list_head *plist, *phead;
> +	struct list_head *phead;
>  	u8	ac_index;
>  	struct tx_servq	*ptxservq;
>  	struct pkt_attrib	*pattrib;
> -	struct xmit_frame	*pxmitframe;
> +	struct xmit_frame	*pxmitframe, *n;
>  	struct hw_xmit *phwxmits =  padapter->xmitpriv.hwxmits;
>  
>  	phead = get_list_head(pframequeue);
> -	list_for_each(plist, phead) {
> -		pxmitframe = list_entry(plist, struct xmit_frame, list);
> -
> +	list_for_each_entry_safe(pxmitframe, n, phead, list) {
>  		xmitframe_enqueue_for_sleeping_sta(padapter, pxmitframe);
>  
>  		pattrib = &pxmitframe->attrib;
> -- 
> 2.30.2
>