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

Guenter Roeck
2021-06-09T10:36:52Z

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
>