kernel: Bluetooth: L2CAP: Fix user-after-free

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix user-after-free This uses l2capchanholdunlesszero after calling l2capgetchanblah to prevent the following trace: Bluetooth: l2capcore.c:static void l2capchandestroystruct kref kref Bluetooth: chan...