cfg80211/mac80211/ath6kl: acquire wdev lock outside ch_switch_notify
The channel switch notification should be sent under the
wdev/sdata-lock, preferably in the same moment as the channel change
happens, to avoid races by other callers (e.g. start/stop_ap).
This also adds the previously missing sdata_lock protection in
csa_finalize_work.
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 4a5c21e..1d446ac9 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2988,13 +2988,18 @@
struct ieee80211_local *local = sdata->local;
int err, changed = 0;
+ sdata_lock(sdata);
+ /* AP might have been stopped while waiting for the lock. */
+ if (!sdata->vif.csa_active)
+ goto unlock;
+
if (!ieee80211_sdata_running(sdata))
- return;
+ goto unlock;
sdata->radar_required = sdata->csa_radar_required;
err = ieee80211_vif_change_channel(sdata, &changed);
if (WARN_ON(err < 0))
- return;
+ goto unlock;
if (!local->use_chanctx) {
local->_oper_chandef = sdata->csa_chandef;
@@ -3003,11 +3008,13 @@
ieee80211_bss_info_change_notify(sdata, changed);
+ sdata->vif.csa_active = false;
switch (sdata->vif.type) {
case NL80211_IFTYPE_AP:
err = ieee80211_assign_beacon(sdata, sdata->u.ap.next_beacon);
if (err < 0)
- return;
+ goto unlock;
+
changed |= err;
kfree(sdata->u.ap.next_beacon);
sdata->u.ap.next_beacon = NULL;
@@ -3021,20 +3028,22 @@
case NL80211_IFTYPE_MESH_POINT:
err = ieee80211_mesh_finish_csa(sdata);
if (err < 0)
- return;
+ goto unlock;
break;
#endif
default:
WARN_ON(1);
- return;
+ goto unlock;
}
- sdata->vif.csa_active = false;
ieee80211_wake_queues_by_reason(&sdata->local->hw,
IEEE80211_MAX_QUEUE_MAP,
IEEE80211_QUEUE_STOP_REASON_CSA);
cfg80211_ch_switch_notify(sdata->dev, &sdata->csa_chandef);
+
+unlock:
+ sdata_unlock(sdata);
}
static int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,