From: Felix Fietkau nbd@nbd.name
[ 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@nbd.name Acked-by: Toke Høiland-Jørgensen toke@kernel.org Link: https://lore.kernel.org/r/20220531190824.60019-1-nbd@nbd.name Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 41531478437c..15a73b7fdd75 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 682a164f795a..8ed877a42f71 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;