From: Steven Rostedt <rostedt@xxxxxxxxxxx>
While looking at a crash report on a timer list being corrupted, which
usually happens when a timer is freed while still active. This is
commonly triggered by code calling del_timer() instead of
del_timer_sync() just before freeing.
One possible culprit is the hci_qca driver, which does exactly that.
Eric mentioned that wake_retrans_timer could be rearmed via the work
queue, so also move the destruction of the work queue before
del_timer_sync().
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 0ff252c1976da ("Bluetooth: hciuart: Add support QCA chipset for UART")
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
Changes since v1: https://lkml.kernel.org/r/20220404182236.1caa174e@xxxxxxxxxxxxxxxxxxxx
- Moved destroy_workqueue() before del_timer_sync() calls (Eric Dumazet).
drivers/bluetooth/hci_qca.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index f6e91fb432a3..eab34e24d944 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -696,9 +696,9 @@ static int qca_close(struct hci_uart *hu)
skb_queue_purge(&qca->tx_wait_q);
skb_queue_purge(&qca->txq);
skb_queue_purge(&qca->rx_memdump_q);
- del_timer(&qca->tx_idle_timer);
- del_timer(&qca->wake_retrans_timer);
destroy_workqueue(qca->workqueue);
+ del_timer_sync(&qca->tx_idle_timer);
+ del_timer_sync(&qca->wake_retrans_timer);
qca->hu = NULL;
kfree_skb(qca->rx_skb);
--
2.35.1
