CVE-2026-43019 Bluetooth: hci_conn: fix potential UAF in set_cig_params_sync

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hciconn: fix potential UAF in setcigparamssync hciconn lookup and field access must be covered by hdev lock in setcigparamssync, otherwise it's possible it is freed concurrently. Take hdev lock to prevent hciconn from...