In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: free the skb when the DLC has no owner rfcomm_recv_

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: RFCOMM: free the skb when the DLC has no owner

rfcomm_recv_data() hands the skb to d->data_ready() and returns 0
without freeing it, so the callback owns the skb from that point on.
The tty implementation frees it when the DLC has been detached from its
device:

static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc,
struct sk_buff *skb)
{
struct rfcomm_dev *dev = dlc->owner;

 1      if (!dev) {
 2              kfree_skb(skb);
 3              return;
 4      }

The socket implementation returns without freeing it, and the skb is
leaked.

A connected DLC can have no owner: rfcomm_sock_destruct() clears
d->owner, while the DLC itself stays on the session until it is closed.
Data frames that arrive in that window still find d->state ==
BT_CONNECTED in rfcomm_recv_data() and are handed to the callback, one
leaked skb each.

The leak does not stop on its own either. The remote runs out of
credits only once RFCOMM_RX_THROTTLED is set, and for a socket the only
place that sets it is rfcomm_sk_data_ready() itself, below the return.
rfcomm_process_dlcs() keeps granting credits, so the remote keeps
sending and the leak keeps growing.

Free the skb, as the tty side does.