On 6/16/25 8:12 PM, Dmitry Antipov wrote:
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>
Acked-by: Christian Lamparter <chunkeey@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
v2: prefer pr_warn_once() over WARN_ON_ONCE()
---
drivers/net/wireless/ath/carl9170/usb.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/ath/carl9170/usb.c b/drivers/net/wireless/ath/carl9170/usb.c
index a3e03580cd9f..564ca6a61985 100644
--- a/drivers/net/wireless/ath/carl9170/usb.c
+++ b/drivers/net/wireless/ath/carl9170/usb.c
@@ -438,14 +438,21 @@ 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).
*/
- ieee80211_queue_work(ar->hw, &ar->ping_work);
+ if (ar->registered)
+ ieee80211_queue_work(ar->hw, &ar->ping_work);
+ else
+ pr_warn_once("device %s is not registered\n",
+ dev_name(&ar->udev->dev));
}
} else {
/*
