Commit f856373e authored by Felix Fietkau's avatar Felix Fietkau Committed by Johannes Berg
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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: default avatarFelix Fietkau <nbd@nbd.name>
Acked-by: default avatarToke Høiland-Jørgensen <toke@kernel.org>
Link: https://lore.kernel.org/r/20220531190824.60019-1-nbd@nbd.name


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent a4926abb

net/mac80211/iface.c

+2 −0
Original line number Diff line number Diff line
@@ -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)

net/mac80211/util.c

+3 −0
Original line number Diff line number Diff line
@@ -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;