Re: [PATCH 1/6] staging: rtl8188eu: use safe iterator in rtw_free_network_queue

From: Christophe JAILLET
Date: Sun May 16 2021 - 16:03:20 EST

Le 16/05/2021 à 18:06, Martin Kaiser a écrit :
rtw_free_network_queue iterates over the scanned wireless networks and
calls _rtw_free_network for each of them. In some cases,
_rtw_free_network removes a network from the list.

We have to use list_for_each_safe if we remove list entries while we
iterate over a list.

Fixes: 23017c8842d2 ("staging: rtl8188eu: Use list iterators and helpers")
Signed-off-by: Martin Kaiser <martin@xxxxxxxxx>
Without this patch, it's easy to get the driver into an endless loop by
scanning, connecting and disconnecting repeatedly.

wpa_supplicant -B -Dwext -i wlan0 -c /path/to/my/config...
while true ; do
sleep 1
wpa_cli reconfigure
wpa_cli add_network
wpa_cli set_network 0 ssid ...
wpa_cli set_network 0 psk ...
wpa_cli select_network 0
sleep 6
wpa_cli status
wpa_cli disconnect 0

drivers/staging/rtl8188eu/core/rtw_mlme.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_mlme.c b/drivers/staging/rtl8188eu/core/rtw_mlme.c
index 159465b073c2..14816ad51668 100644
--- a/drivers/staging/rtl8188eu/core/rtw_mlme.c
+++ b/drivers/staging/rtl8188eu/core/rtw_mlme.c
@@ -199,7 +199,7 @@ struct wlan_network *rtw_find_network(struct __queue *scanned_queue, u8 *addr)
void rtw_free_network_queue(struct adapter *padapter, u8 isfreeall)
- struct list_head *phead, *plist;
+ struct list_head *phead, *plist, *temp;
struct wlan_network *pnetwork;
struct mlme_priv *pmlmepriv = &padapter->mlmepriv;
struct __queue *scanned_queue = &pmlmepriv->scanned_queue;
@@ -207,7 +207,7 @@ void rtw_free_network_queue(struct adapter *padapter, u8 isfreeall)
phead = get_list_head(scanned_queue);
- list_for_each(plist, phead) {
+ list_for_each_safe(plist, temp, phead) {
pnetwork = list_entry(plist, struct wlan_network, list);
_rtw_free_network(pmlmepriv, pnetwork, isfreeall);

Nitpicking: 'list_for_each_entry_safe' could also be used to simplify code.