In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: free the HCI command when it is cancelled mgmt_hci_cmd_sync() queues the pending command with a NULL destroy callback, so it is only freed if send_hci_cmd_sync() 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. The now-empty done label is replaced by a direct return.
https://git.kernel.org/stable/c/e0cd7b34dc6b5414cac3d4cd376f73d3e9ffbd93
https://git.kernel.org/stable/c/481533b03985177ddc805e0bd12fc07e7adf9040
https://git.kernel.org/stable/c/414b365ecea6c30357adee6b8a7c5edc03a03575