In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: free the mesh send cancel command when it is cancelled

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

Bluetooth: MGMT: free the mesh send cancel command when it is cancelled

mesh_send_cancel() queues the pending command with a NULL destroy
callback, so it is only freed if send_cancel() runs. A cancelled entry is
leaked, as _hci_cmd_sync_cancel_entry() does not release entry->data when
there is no destroy callback, and hci_cmd_sync_clear() cancels every
pending entry when the controller is unregistered. Nothing else reclaims
it either: mgmt_pending_new() does not put the command on
hdev->mgmt_pending.

The leak also pins the socket reference taken by mgmt_pending_new(), so
the mgmt socket is never released.

Free the command from a destroy callback.