wifi: mac80211: do not wake queues on a vif that is being stopped

When a vif is being removed and sdata->bss is cleared, __ieee80211_wake_txqs can still be called on it, which crashes as soon as sdata->bss is being dereferenced. To fix this properly, check for SDATA_STATE_RUNNING before waking queues, and take the fq lock when setting it (to ensure that __ieee80211_wake_txqs observes the change when running on a different CPU) Signed-off-by: Felix Fietkau <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Johannes Berg <[email protected]>
kubalewski · Jun 29, 2022 · f856373 · f856373
1 parent a4926ab
commit f856373
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diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
@@ -377,7 +377,9 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, bool going_do
 	bool cancel_scan;
 	struct cfg80211_nan_func *func;
 
+	spin_lock_bh(&local->fq.lock);
 	clear_bit(SDATA_STATE_RUNNING, &sdata->state);
+	spin_unlock_bh(&local->fq.lock);
 
 	cancel_scan = rcu_access_pointer(local->scan_sdata) == sdata;
 	if (cancel_scan)

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
@@ -301,6 +301,9 @@ static void __ieee80211_wake_txqs(struct ieee80211_sub_if_data *sdata, int ac)
 	local_bh_disable();
 	spin_lock(&fq->lock);
 
+	if (!test_bit(SDATA_STATE_RUNNING, &sdata->state))
+		goto out;
+
 	if (sdata->vif.type == NL80211_IFTYPE_AP)
 		ps = &sdata->bss->ps;