CVE-2026-45836 Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_get_sndtimeo_cb()

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix null-ptr-deref in l2capsockgetsndtimeocb Add the same NULL guard already present in l2capsockresumecb and l2capsockreadycb...