[PATCH] Bluetooth: hci_sync: Fix queuing commands when HCI_UNREGISTER is set

From: Luiz Augusto von Dentz <redacted>

hci_cmd_sync_queue shall return an error if HCI_UNREGISTER flag has
been set as that means hci_unregister_dev has been called so it will
likely cause a uaf after the timeout as the hdev will be freed.

Signed-off-by: Luiz Augusto von Dentz <redacted>
---
 net/bluetooth/hci_sync.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 87c46b04b9ff..af16b1018c35 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c

@@ -382,6 +382,9 @@ int hci_cmd_sync_queue(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
 {
 	struct hci_cmd_sync_work_entry *entry;
 
+	if (hci_dev_test_flag(hdev, HCI_UNREGISTER))
+		return -ENODEV;
+
 	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 	if (!entry)
 		return -ENOMEM;

-- 
2.34.1