Syzkaller reports [1, 2] crashes caused by an attempts to ping the device which has failed to load firmware. Since such a device doesn't pass 'ieee80211_register_hw()', an internal workqueue managed by 'ieee80211_queue_work()' is not yet created and an attempt to queue work on it causes null-ptr-deref. [1] https://syzkaller.appspot.com/bug?extid=9a4aec827829942045ff [2] https://syzkaller.appspot.com/bug?extid=0d8afba53e8fb2633217 Fixes: e4a668c59080 ("carl9170: fix spurious restart due to high latency") Signed-off-by: Dmitry Antipov <dmantipov@xxxxxxxxx> --- drivers/net/wireless/ath/carl9170/usb.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/ath/carl9170/usb.c b/drivers/net/wireless/ath/carl9170/usb.c index a3e03580cd9f..a0bfa0c477ee 100644 --- a/drivers/net/wireless/ath/carl9170/usb.c +++ b/drivers/net/wireless/ath/carl9170/usb.c @@ -438,13 +438,18 @@ static void carl9170_usb_rx_complete(struct urb *urb) if (atomic_read(&ar->rx_anch_urbs) == 0) { /* - * The system is too slow to cope with - * the enormous workload. We have simply - * run out of active rx urbs and this - * unfortunately leads to an unpredictable - * device. + * At this point, either the system is too slow to + * cope with the enormous workload (so we have simply + * run out of active rx urbs and this unfortunately + * leads to an unpredictable device), or the device + * is not fully functional after an unsuccessful + * firmware loading attempts (so it doesn't pass + * ieee80211_register_hw() and there is no internal + * workqueue at all). */ + if (WARN_ON_ONCE(!ar->registered)) + return; ieee80211_queue_work(ar->hw, &ar->ping_work); } } else { -- 2.49.0
