[PATCH] Bluetooth: Initialize the TX queue lock when creating struct l2cap_chan in 6LOWPAN

[Coiby Xu]

When L2CAP channel is destroyed by hci_unregister_dev, it will
acquire the spin lock of the (struct l2cap_chan *)->tx_q list to
delete all the buffers. But sometimes when hci_unregister_dev is
being called, this lock may have not bee initialized. Initialize
the TX queue lock when creating struct l2cap_chan in 6LOWPAN to fix
this problem.

Reported-by: syzbot+fadfba6a911f6bf71842@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://syzkaller.appspot.com/bug?extid=fadfba6a911f6bf71842
Signed-off-by: Coiby Xu <coiby.xu@xxxxxxxxx>
---
 net/bluetooth/6lowpan.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index bb55d92691b0..713c618a73df 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -651,6 +651,7 @@ static struct l2cap_chan *chan_create(void)
 
 	l2cap_chan_set_defaults(chan);
 
+	skb_queue_head_init(&chan->tx_q);
 	chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 	chan->mode = L2CAP_MODE_LE_FLOWCTL;
 	chan->imtu = 1280;
-- 
2.27.0