From: Felix Fietkau <nbd@xxxxxxxx> [ Upstream commit f856373e2f31ffd340e47e2b00027bd4070f74b3 ] 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 <nbd@xxxxxxxx> Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220531190824.60019-1-nbd@xxxxxxxx Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/mac80211/iface.c | 2 ++ net/mac80211/util.c | 3 +++ 2 files changed, 5 insertions(+) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 041859b5b71d..1f6878a14fff 100644 --- 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 index be1911d8089f..d85a39a7b843 100644 --- 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; -- 2.35.1
