Re: [PATCH 6/7] staging: rtl8188eu: use safe iterator in rtl8188eu_xmitframe_complete()

Guenter Roeck
2021-06-09T10:38:15Z

On Mon, Jun 07, 2021 at 09:18:25PM +0300, Dan Carpenter wrote:
> This loop calls rtw_free_xmitframe(pxmitpriv, pxmitframe) which removes
> "pxmitframe" (our list iterator) from the list. So to prevent a forever
> loop we need to use a safe list iterator.
>
> 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/hal/rtl8188eu_xmit.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/staging/rtl8188eu/hal/rtl8188eu_xmit.c b/drivers/staging/rtl8188eu/hal/rtl8188eu_xmit.c
> index 10a8dcc6ca95..19055a1a92c1 100644
> --- a/drivers/staging/rtl8188eu/hal/rtl8188eu_xmit.c
> +++ b/drivers/staging/rtl8188eu/hal/rtl8188eu_xmit.c
> @@ -414,6 +414,7 @@ bool rtl8188eu_xmitframe_complete(struct adapter *adapt,
> struct xmit_priv *pxmitpriv)
> {
> struct xmit_frame *pxmitframe = NULL;
> + struct xmit_frame *n;
> struct xmit_frame *pfirstframe = NULL;
> struct xmit_buf *pxmitbuf;
>
> @@ -422,7 +423,7 @@ bool rtl8188eu_xmitframe_complete(struct adapter *adapt,
> struct sta_info *psta = NULL;
> struct tx_servq *ptxservq = NULL;
>
> - struct list_head *xmitframe_plist = NULL, *xmitframe_phead = NULL;
> + struct list_head *xmitframe_phead = NULL;
>
> u32 pbuf; /* next pkt address */
> u32 pbuf_tail; /* last pkt tail */
> @@ -507,10 +508,7 @@ bool rtl8188eu_xmitframe_complete(struct adapter *adapt,
> spin_lock_bh(&pxmitpriv->lock);
>
> xmitframe_phead = get_list_head(&ptxservq->sta_pending);
> - list_for_each(xmitframe_plist, xmitframe_phead) {
> - pxmitframe = list_entry(xmitframe_plist, struct xmit_frame,
> - list);
> -
> + list_for_each_entry_safe(pxmitframe, n, xmitframe_phead, list) {
> pxmitframe->agg_num = 0; /* not first frame of aggregation */
> pxmitframe->pkt_offset = 0; /* not first frame of aggregation, no need to reserve offset */
>
> --
> 2.30.2
>