[PATCH 47/65] staging: wfx: fix bss_loss

Jérôme Pouiller
2020-01-15T12:13:45Z

wfx_tx_confirm_cb() retrieves the station associated with a frame using
the MAC address from the 802.11 header. In the other side wfx_tx()
retrieves the station using sta field from the ieee80211_tx_control
argument.

In wfx_cqm_bssloss_sm(), wfx_tx() was called directly without valid sta
field, but with a valid MAC address in 802.11 header. So there the
processing of this packet was unbalanced and may produce weird bugs.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
---
drivers/staging/wfx/sta.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/wfx/sta.c b/drivers/staging/wfx/sta.c
index aebce96dcd4a..80a2a9e8256f 100644
--- a/drivers/staging/wfx/sta.c
+++ b/drivers/staging/wfx/sta.c
@@ -88,19 +88,25 @@ void wfx_cqm_bssloss_sm(struct wfx_vif *wvif, int init, int good, int bad)
// FIXME: call ieee80211_beacon_loss/ieee80211_connection_loss instead
if (tx) {
struct sk_buff *skb;
+ struct ieee80211_hdr *hdr
+ struct ieee80211_tx_control control = { };

wvif->bss_loss_state++;

skb = ieee80211_nullfunc_get(wvif->wdev->hw, wvif->vif, false);
if (!skb)
goto end;
+ hdr = (struct ieee80211_hdr *)skb->data;
memset(IEEE80211_SKB_CB(skb), 0,
sizeof(*IEEE80211_SKB_CB(skb)));
IEEE80211_SKB_CB(skb)->control.vif = wvif->vif;
IEEE80211_SKB_CB(skb)->driver_rates[0].idx = 0;
IEEE80211_SKB_CB(skb)->driver_rates[0].count = 1;
IEEE80211_SKB_CB(skb)->driver_rates[1].idx = -1;
- wfx_tx(wvif->wdev->hw, NULL, skb);
+ rcu_read_lock(); // protect control.sta
+ control.sta = ieee80211_find_sta(wvif->vif, hdr->addr1);
+ wfx_tx(wvif->wdev->hw, &control, skb);
+ rcu_read_unlock();
}
end:
mutex_unlock(&wvif->bss_loss_lock);
--
2.25.0