kernel: Bluetooth: rfcomm: Fix null-ptr-deref in rfcomm_check_security

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: rfcomm: Fix null-ptr-deref in rfcommchecksecurity The Linux kernel CVE team has assigned CVE-2024-26903 to this issue. Upstream advisory: https://lore.kernel.org/linux-cve-announce/2024041745-CVE-2024-26903-de5c@gregkh...