staging: wfx: fix RCU usage

Indeed, sta was used after call to rcu_unlock()

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200115135338.14374-49-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/wfx/sta.c b/drivers/staging/wfx/sta.c
index 1c10ebd119440fcde8d34342d43c2da2e87f3dff..cc72877a090f287172958d4c84a07f3d1686b6a8 100644 (file)
--- a/drivers/staging/wfx/sta.c
+++ b/drivers/staging/wfx/sta.c
@@ -690,10 +690,9 @@ static void wfx_join_finalize(struct wfx_vif *wvif,
        struct ieee80211_sta *sta = NULL;
 
        wvif->beacon_int = info->beacon_int;
-       rcu_read_lock();
+       rcu_read_lock(); // protect sta
        if (info->bssid && !info->ibss_joined)
                sta = ieee80211_find_sta(wvif->vif, info->bssid);
-       rcu_read_unlock();
        if (sta)
                wvif->bss_params.operational_rate_set =
                        wfx_rate_mask_to_hw(wvif->wdev, sta->supp_rates[wvif->channel->band]);
@@ -712,6 +711,7 @@ static void wfx_join_finalize(struct wfx_vif *wvif,
        wvif->bss_params.aid = info->aid;
 
        hif_set_association_mode(wvif, info, sta ? &sta->ht_cap : NULL);
+       rcu_read_unlock();
 
        if (!info->ibss_joined) {
                hif_keep_alive_period(wvif, 30 /* sec */);