diff mbox series

[v1,2/2] Bluetooth: hci_serdev: Add protocol check in hci_uart_dequeue().

Message ID 20180822120412.20285-3-bgodavar@codeaurora.org (mailing list archive)
State Not Applicable, archived
Delegated to: Andy Gross
Headers show
Series Fix for proto races in hci_serdev. | expand

Commit Message

Balakrishna Godavarthi Aug. 22, 2018, 12:04 p.m. UTC
This will help to check the status of protocol while dequeuing an
skb packet. In some instaces we will end up kernel crash,
where proto close is called and we trying to dequeue an packet.

[  500.142902] [<ffffff80080f9ce4>] do_raw_spin_lock+0x1c/0xe0
[  500.148643] [<ffffff80088f1c7c>] _raw_spin_lock_irqsave+0x38/0x48
[  500.154917] [<ffffff8008780ce8>] skb_dequeue+0x28/0x84
[  500.160209] [<ffffff8000ad6f48>] 0xffffff8000ad6f48
[  500.165230] [<ffffff8000ad6610>] 0xffffff8000ad6610
[  500.170257] [<ffffff80080c7ce8>] process_one_work+0x238/0x3e4
[  500.176174] [<ffffff80080c8330>] worker_thread+0x2bc/0x3d4
[  500.181821] [<ffffff80080cdabc>] kthread+0x138/0x140
[  500.186945] [<ffffff80080844e0>] ret_from_fork+0x10/0x18

Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
---
 drivers/bluetooth/hci_serdev.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
index 46e20444ba19..a541e6ee085e 100644
--- a/drivers/bluetooth/hci_serdev.c
+++ b/drivers/bluetooth/hci_serdev.c
@@ -57,9 +57,10 @@  static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
 {
 	struct sk_buff *skb = hu->tx_skb;
 
-	if (!skb)
-		skb = hu->proto->dequeue(hu);
-	else
+	if (!skb) {
+		if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
+			skb = hu->proto->dequeue(hu);
+	} else
 		hu->tx_skb = NULL;
 
 	return skb;