Re: [PATCH 2/6] staging: rtl8188eu: use safe iterator in rtw_free_all_stainfo

Guenter Roeck
2021-05-16T19:24:37Z

On Sun, May 16, 2021 at 06:06:09PM +0200, Martin Kaiser wrote:
> This is another case where we may remove list entries while we iterate over
> the list. Use list_for_each_safe to avoid an endless loop.
>
> Fixes: 23017c8842d2 ("staging: rtl8188eu: Use list iterators and helpers")
> Signed-off-by: Martin Kaiser <martin@kaiser.cx>

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

> ---
> Without this patch, unloading the module goes into an endless loop
> sometimes.
>
> drivers/staging/rtl8188eu/core/rtw_sta_mgt.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/rtl8188eu/core/rtw_sta_mgt.c b/drivers/staging/rtl8188eu/core/rtw_sta_mgt.c
> index 7941ca0397ed..eda7a441acde 100644
> --- a/drivers/staging/rtl8188eu/core/rtw_sta_mgt.c
> +++ b/drivers/staging/rtl8188eu/core/rtw_sta_mgt.c
> @@ -379,7 +379,7 @@ u32 rtw_free_stainfo(struct adapter *padapter, struct sta_info *psta)
> /* free all stainfo which in sta_hash[all] */
> void rtw_free_all_stainfo(struct adapter *padapter)
> {
> - struct list_head *plist, *phead;
> + struct list_head *plist, *phead, *temp;
> s32 index;
> struct sta_info *psta = NULL;
> struct sta_priv *pstapriv = &padapter->stapriv;
> @@ -392,7 +392,7 @@ void rtw_free_all_stainfo(struct adapter *padapter)
>
> for (index = 0; index < NUM_STA; index++) {
> phead = &pstapriv->sta_hash[index];
> - list_for_each(plist, phead) {
> + list_for_each_safe(plist, temp, phead) {
> psta = list_entry(plist, struct sta_info, hash_list);
>
> if (pbcmc_stainfo != psta)
> --
> 2.20.1
>