From: Johannes Berg <johannes.berg@xxxxxxxxx> Syzbot reports that we may be able to get into a situation where mac80211 has pending ACK frames on shutdown with hwsim. It appears that the reason for this is that syzbot uses the wmediumd hooks to intercept/injection frames, and may shut down hwsim, removing the radio(s), while frames are pending in the air simulation. Clean out the pending queue when the interface is stopped, after this the frames can't be reported back to mac80211 properly anyway. Reported-by: syzbot+a063bbf0b15737362592@xxxxxxxxxxxxxxxxxxxxxxxxx #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ master Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> --- drivers/net/wireless/mac80211_hwsim.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 51ce767eaf88..7a6fd46d0c6e 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -1693,8 +1693,13 @@ static int mac80211_hwsim_start(struct ieee80211_hw *hw) static void mac80211_hwsim_stop(struct ieee80211_hw *hw) { struct mac80211_hwsim_data *data = hw->priv; + data->started = false; hrtimer_cancel(&data->beacon_timer); + + while (!skb_queue_empty(&data->pending)) + ieee80211_free_txskb(hw, skb_dequeue(&data->pending)); + wiphy_dbg(hw->wiphy, "%s\n", __func__); } -- 2.31.1