CVE-2025-38489 is a medium severity vulnerability in the Linux kernel affecting the s390 architecture's BPF implementation. A previous fix for handling a NULL new_addr in the bpf_arch_text_poke() function was accidentally removed, causing intermittent kernel panics in certain BPF programs such as perf's on_switch(). The issue has been corrected by restoring the original fix and adding clarifying comments.