In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_event: validate skb length for unknown CC opcode
In hci_cmd_complete_evt(), if the command complete event has an unknown opcode, we assume the first byte of the remaining skb->data contains the return status. However, parameter data has previously been pulled in hci_event_func(), which may leave the skb empty. If so, using skb->data[0] for the return status uses un-init memory.
The fix is to check skb->len before using skb->data.