CVE-2024-43840 is a vulnerability in the Linux kernel's BPF trampoline code on arm64 architectures. The issue arises because the trampoline incorrectly handles addresses of bpf_tramp_image allocated with kzalloc(), which can exceed 48 bits. This causes the trampoline to pass invalid addresses to kernel functions, leading to a kernel crash. The vulnerability has a medium severity with an impact on availability due to potential crashes.